Apparatus, system, and method for a device shared between multiple independent hosts

ABSTRACT

The invention includes a proxy request receiver module and a proxy request command module. The proxy request receiver module executes on a designated command proxy host and receives a proxy request from a requesting host. The requesting host is one of two or more hosts. Each of the hosts executes an operating system independent from the other hosts and a shared device. One of the hosts is designated as the command proxy host. A system bus connects the hosts and shared device. The proxy request includes a control request to be executed by the shared device sufficient to configure the shared device for a data transfer between the requesting host and shared device independent of the command proxy host. The control request is free of data. The proxy request command module transmits the control request to the shared device.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of and claims priority to U.S. Provisional Patent Application No. 60/873,111 entitled “Elemental Blade System” and filed on Dec. 6, 2006 for David Flynn, et al., and U.S. Provisional Patent Application No. 60/974,470 entitled “Apparatus, System, and Method for Object-Oriented Solid-State Storage” and filed on Sep. 22, 2007 for David Flynn, et al., which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to device management and more particularly relates to sharing a device between multiple dependent hosts.

2. Description of the Related Art

Traditionally, computer components, such as a network interface (network interface card or “NIC”), storage devices, graphics cards, etc. connect to a processor of a host computer through a system bus. Traditional system buses are limited in the number of devices that can be connected and act somewhat like a group of wires that physically connect to a limited number of devices. Some system bus protocols, such as small computer system interface (“SCSI”), Institute of Electrical and Electronics Engineers (“IEEE”) 1394 (FireWire), Fiber Channel, universal serial bus (“USB”), peripheral component interconnect express (“PCI-e”) bus, a Serial Advanced Technology Attachment (“serial ATA”) bus, or the like, allow connection of external devices.

Many modern system buses, such as PCIe, use point to point connectivity and switch chips to interconnect multiple devices, while retaining traditional system bus functionality. However, when a device, such as a storage device, network interface (network interface card or “NIC”), etc. connected to a system bus is shared between multiple devices, the shared device is typically controlled through a single host. Data and commands from other hosts seeking access to the shared device pass through the host to the shared device and from the shared device through the controlling host back to the other hosts. This is inefficient because the requesting hosts have no ability to communicate directly to the shared device for data transfers. This precludes direct memory access (“DMA”) transfers and remote DMA (“RDMA”) transfers between the requesting hosts and the shared device.

SUMMARY OF THE INVENTION

From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that permits for sharing a device between multiple hosts where data can be transferred between a host and the shared device over a system bus independent from other hosts connected to the system bus. Beneficially, such an apparatus, system, and method would allow a command proxy host to establish data path between the shared device and requesting host and then act as proxy for selected commands used to set up a data transfer.

The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available systems for sharing a device between multiple hosts. Accordingly, the present invention has been developed to provide an apparatus, system, and method for sharing a device between multiple hosts that overcome many or all of the above-discussed shortcomings in the art.

The apparatus is provided, in one embodiment, with a plurality of modules for implementing the sharing of a device between multiple hosts including a proxy request receiver module and a proxy request command module. The proxy request receiver module typically executes on a designated command proxy host and receives a proxy request from a requesting host. The requesting host is typically one of two or more hosts, and each of the two or more hosts executes an operating system independent from the other hosts and a shared device. One of the two or more hosts is designated as the command proxy host, and the two or more hosts and the shared device may be connected through a system bus. The proxy request may include a control request to be executed by the shared device. The control request is typically sufficient to configure the shared device for a data transfer between the requesting host sending the proxy request and the shared device. The data transfer executes independent of the command proxy host, and the control request is typically substantially free of data to be transferred between the requesting host and the shared device. The proxy request command module typically executes on the command proxy host and transmits the control request to the shared device in response to the proxy request receiver module receiving the control request.

In one embodiment, the apparatus includes an interrupt receiver module and an interrupt transmission module. The interrupt receiver module typically executes on the command proxy host and receives an interrupt from the shared device. The interrupt may include information that the shared device has data to be transmitted to a host or has already transmitted data to a host. The interrupt transmission module transmits the information included in the interrupt to the host. The information is sufficient for the host receiving the information to continue a process of receiving the data transmission. In a further embodiment, the hosts other than the command proxy host are incapable of receiving the interrupt.

In one embodiment of the apparatus, the apparatus includes a path module that typically executes in the command proxy host. The path module determines if a communication path exists between a host and the shared device. The communication path may include a data path or a command path. The path module creates the communication path in response to determining that the communication path does not exist, and the data path is sufficient to transfer data or control requests between the host and the shared device. In a further embodiment, the communication path module may determine if a communication path exists in response to a proxy request from the host or an interrupt from the shared device.

In an additional embodiment, the shared device may be a network interface that transfers data received from one of the two or more hosts over a computer network to a device and that transfers data received through a computer network from a device to one of the two or more hosts. In another embodiment, the shared device may include one or more of a storage device and a storage controller. In a further embodiment, the storage device further may be a solid-state storage device, and the storage controller may be a solid-state storage controller.

In one embodiment, the system bus may be a peripheral component interconnect express (“PCI-e”). In a further embodiment, the PCI-e bus and the shared device supports PCI-e input/output virtualization (“PCIe-IOV”). In yet a further embodiment, two or more of the two or more hosts share the shared device within a single context.

In one embodiment of the apparatus, the command proxy host executes in a root. In another embodiment, the command proxy host executes in one of the two or more hosts. In yet another embodiment, the command proxy host executes in the shared device. In another embodiment, the command proxy host executes in a third party element managing commands to the shared device independent of the two or more hosts. In yet another embodiment, the command proxy host executes in a device that combines one or more of the root, one of the hosts, the shared device, and the third party element.

In one embodiment, the independent operating systems include a virtual machine layer with one or more operating systems operating above the virtual machine layer. In another embodiment, the shared device uses one of direct memory access (“DMA”) and remote direct memory access (“RDMA”) to transfer data between the host identified in the control request and the shared device. In yet another embodiment, the apparatus includes a standard device emulation module that typically executes on the command proxy bus. The standard device emulation module emulates a device to one or more of the hosts as a standard device attached to the system bus prior to loading the one or more hosts with code specific to the operation of the device. The standard device may be supported by an industry standard BIOS. In a further embodiment, the device emulated by the standard device emulation module comprises the shared device. In yet a further embodiment, the standard device emulation module for the standard device supports I/O virtualization.

In one embodiment of the apparatus, the system bus includes a system bus switch with a non-transparent port. A first initialization process executing on a host discovers at least the command proxy host to the host and is unable to discover the shared device. The discovered command proxy host is identified for communication with at least the host executing the first initialization process as a result of the first initialization process. In a further embodiment, a second initialization process executing on the command proxy host discovers at least the shared device to the command proxy host, and the shared device is identified for communication with at least the command proxy host as a result of the initialization process.

In an alternate embodiment of the apparatus, the apparatus may include a shared device control request receiver module and a control request response module. The shared device control request receiver module typically executes on the shared device and receives a control request from a host designated as a command proxy host. The command proxy host is one of two or more hosts, and each of the two or more hosts execute an operating system independent from the other hosts and the shared device. The two or more hosts and the shared device are connected through a system bus. The command proxy host transmits the control request in response to receiving a proxy request from a requesting host, and the requesting host is one of the two or more hosts. The control request response module typically executes on the shared device and configures the shared device for a data transfer between the requesting host and the shared device. The control request is substantially free of data of the data transfer, and the data transfer executes independent of the command proxy host.

In one embodiment, the interrupt transmission module transmits an interrupt to the command proxy host. The interrupt may include information that one of the shared devices has data to be transmitted to a host or that the shared device has transferred data to a host. The information is typically sufficient for the host to continue a process of receiving the data. The command proxy host transmits the information to the host.

In another alternate embodiment of the apparatus, the apparatus may include a proxy request transmitter module and a host data transmitter module. The proxy request transmitter module transmits a proxy request from a requesting host to a designated command proxy host. The requesting host and the command proxy host each may be one of two or more hosts or a shared device connected to a system bus. Each of the two or more hosts execute an operating system independent from the other hosts and the shared device, and the proxy request includes a control request to be executed by the shared device. The command proxy host transmits the control request to the shared device, and the control request is sufficient to configure the shared device for a data transfer between the shared device and the requesting host transmitting the proxy request. The control request is substantially free of data to be transferred between the requesting host and the shared device. The host data transmitter module is typically executes on the requesting host and initiates transfer of data between the requesting host and the shared device. The transfer executes independent of the command proxy host.

In one embodiment, the apparatus may include a host interrupt receiver module and a host data receiver module. The host interrupt receiver module typically executes on a host and receives information from the command proxy host that the shared device has data to be transmitted to the host or already transmitted data to the host. The information may be derived from an interrupt received by the command proxy host from the shared device. The host data receiver module continues a process of receiving the data transmission, and the data transmission executes independent of the command proxy host.

A system of the present invention is also presented. The system substantially includes the modules and embodiments described above with regard to the apparatus. In one embodiment, the system includes a system bus, a shared device connected to the system bus, and a two or more hosts connected to the system bus. Each of the two or more hosts execute an operating system independent from the other hosts and the shared device, and one of the two or more hosts is a designated command proxy host. The system may also include a proxy request receiver module and a proxy request command module. The proxy request receiver module may execute on the command proxy host. The proxy receiver module receives a proxy request from a requesting host, and the proxy request is sufficient to configure the shared device for a data transfer between the requesting host sending the proxy request and the shared device. The data transfer executes independent of the command proxy host, and the control request may be substantially free of data to be transferred between the requesting host and the shared device. The proxy request command module may execute on the command proxy host and transmits the control request to the shared device in response to the proxy request receiver module receiving the control request.

A method of the present invention is also presented for sharing a device between multiple hosts. The method in the disclosed embodiments substantially includes the steps necessary to carry out the functions presented above with respect to the operation of the described apparatus and system. In one embodiment, the method includes receiving a proxy request from a requesting host and transmitting the control request to the shared device in response to the proxy request receiver module receiving the control request. The requesting host may be one of two or more hosts, and each of the two or more hosts may execute an operating system independent from the other hosts and a shared device. One of the two or more hosts is designated as the command proxy host, and the two or more hosts and the shared device are connected through a system bus. The proxy request may include a control request to be executed by the shared device. The control request is typically sufficient to configure the shared device for a data transfer between the requesting host sending the proxy request and the shared device. The data transfer executes independent of the command proxy host, and the control request may be substantially free of data to be transferred between the requesting host and the shared device.

In an alternate embodiment, the method may include receiving a control request from a host designated as a command proxy host and configuring the shared device for a data transfer between the requesting host and the shared device. The control request may be substantially free of data of the data transfer and the data transfer may execute independent of the command proxy host.

In yet another embodiment, the method may include transmitting a proxy request from a requesting host to a designated command proxy host and initiating transfer of data between the requesting host and the shared device, the transfer executing independent of the command proxy host. In such an embodiment, the requesting host and the command proxy host may each be one of two or more hosts or a shared device connected to a system bus. Each of the two or more hosts execute an operating system independent from the other hosts and the shared device, and the proxy request includes a control request to be executed by the shared device. The command proxy host transmits the control request to the shared device, and the control request is sufficient to configure the shared device for a data transfer between the shared device and the requesting host transmitting the proxy request. The control request may be substantially free of data to be transferred between the requesting host and the shared device.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.

These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

FIG. 1A is a schematic block diagram illustrating one embodiment of a system for data management in a solid-state storage device in accordance with the present invention;

FIG. 1B is a schematic block diagram illustrating one embodiment of a system for object management in a storage device in accordance with the present invention;

FIG. 1C is a schematic block diagram illustrating one embodiment of a system for an in-server storage area network in accordance with the present invention;

FIG. 2A is a schematic block diagram illustrating one embodiment of an apparatus for object management in a storage device in accordance with the present invention;

FIG. 2B is a schematic block diagram illustrating one embodiment of a solid-state storage device controller in a solid-state storage device in accordance with the present invention;

FIG. 3 is a schematic block diagram illustrating one embodiment of a solid-state storage controller with a write data pipeline and a read data pipeline in a solid-state storage device in accordance with the present invention;

FIG. 4A is a schematic block diagram illustrating one embodiment of a bank interleave controller in the solid-state storage controller in accordance with the present invention;

FIG. 4B is a schematic block diagram illustrating an alternate embodiment of a bank interleave controller in the solid-state storage controller in accordance with the present invention;

FIG. 5A is a schematic flow chart diagram illustrating one embodiment of a method for managing data in a solid-state storage device using a data pipeline in accordance with the present invention;

FIG. 5B is a schematic flow chart diagram illustrating one embodiment of a method for in-server SAN in accordance with the present invention;

FIG. 6 is a schematic flow chart diagram illustrating another embodiment of a method for managing data in a solid-state storage device using a data pipeline in accordance with the present invention;

FIG. 7 is a schematic flow chart diagram illustrating an embodiment of a method for managing data in a solid-state storage device using a bank interleave in accordance with the present invention;

FIG. 8 is a schematic block diagram illustrating one embodiment of an apparatus for garbage collection in a solid-state storage device in accordance with the present invention;

FIG. 9 is a schematic flow chart diagram illustrating one embodiment of a method for garbage collection in a solid state storage device in accordance with the present invention;

FIG. 10 is a schematic block diagram illustrating one embodiment of a system for a device shared between multiple hosts in accordance with the present invention;

FIG. 11 is a schematic block diagram illustrating one embodiment of an apparatus in a command proxy host for a device shared between multiple hosts in accordance with the present invention;

FIG. 12 is a schematic block diagram illustrating one embodiment of an apparatus in a shared device for a device shared between multiple hosts in accordance with the present invention;

FIG. 13 is a schematic block diagram illustrating one embodiment of an apparatus in a requesting host for a device shared between multiple hosts in accordance with the present invention;

FIG. 14 is a schematic flow chart diagram illustrating a first embodiment of a method for a device shared between multiple hosts in accordance with the present invention;

FIG. 15 is a schematic flow chart diagram illustrating a second embodiment of a method for a device shared between multiple hosts in accordance with the present invention; and

FIG. 16 is a schematic flow chart diagram illustrating an third embodiment of a method for a device shared between multiple hosts in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable media.

Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Reference to a signal bearing medium may take any form capable of generating a signal, causing a signal to be generated, or causing execution of a program of machine-readable instructions on a digital processing apparatus. A signal bearing medium may be embodied by a transmission line, a compact disk, digital-video disk, a magnetic tape, a Bernoulli drive, a magnetic disk, a punch card, flash memory, integrated circuits, or other digital processing apparatus memory device.

Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

The schematic flow chart diagrams included herein are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

Solid-State Storage System

FIG. 1A is a schematic block diagram illustrating one embodiment of a system 100 for data management in a solid-state storage device in accordance with the present invention. The system 100 includes a solid-state storage device 102, a solid-state storage controller 104, a write data pipeline 106, a read data pipeline 108, a solid-state storage 110, a computer 112, a client 114, and a computer network 116, which are described below.

The system 100 includes at least one solid-state storage device 102. In another embodiment, the system 100 includes two or more solid-state storage devices 102. Each solid-state storage device 102 may include non-volatile, solid-state storage 110, such as flash memory, nano random access memory (“nano RAM or NRAM”), magneto-resistive RAM (“MRAM”), dynamic RAM (“DRAM”), phase change RAM (“PRAM”), etc. The solid-state storage device 102 is described in more detail with respect to FIGS. 2 and 3. The solid-state storage device 102 is depicted in a computer 112 connected to a client 114 through a computer network 116. In one embodiment, the solid-state storage device 102 is internal to the computer 112 and is connected using a system bus, such as a peripheral component interconnect express (“PCI-e”) bus, a Serial Advanced Technology Attachment (“serial ATA”) bus, or the like. In another embodiment, the solid-state storage device 102 is external to the computer 112 and is connected, a universal serial bus (“USB”) connection, an Institute of Electrical and Electronics Engineers (“IEEE”) 1394 bus (“FireWire”), or the like. In other embodiments, the solid-state storage device 102 is connected to the computer 112 using a peripheral component interconnect (“PCI”) express bus using external electrical or optical bus extension or bus networking solution such as Infiniband or PCI Express Advanced Switching (“PCIe-AS”), or the like.

In various embodiments, the solid-state storage device 102 may be in the form of a dual-inline memory module (“DIMM”), a daughter card, or a micro-module. In another embodiment, the solid-state storage device 102 is an element within a rack-mounted blade. In another embodiment, the solid state storage device 102 is contained within a package that is integrated directly onto a higher level assembly (e.g. mother board, lap top, graphics processor). In another embodiment, individual components comprising the solid-state storage device 102 are integrated directly onto a higher level assembly without intermediate packaging.

The solid-state storage device 102 includes one or more solid-state storage controllers 104, each may include a write data pipeline 106 and a read data pipeline 108 and each includes a solid-state storage 110, which are described in more detail below with respect to FIGS. 2 and 3.

The system 100 includes one or more computers 112 connected to the solid-state storage device 102. A computer 112 may be a host, a server, a storage controller of a storage area network (“SAN”), a workstation, a personal computer, a laptop computer, a handheld computer, a supercomputer, a computer cluster, a network switch, router, or appliance, a database or storage appliance, a data acquisition or data capture system, a diagnostic system, a test system, a robot, a portable electronic device, a wireless device, or the like. In another embodiment, a computer 112 may be a client and the solid-state storage device 102 operates autonomously to service data requests sent from the computer 112. In this embodiment, the computer 112 and solid-state storage device 102 may be connected using a computer network, system bus, or other communication means suitable for connection between a computer 112 and an autonomous solid-state storage device 102.

In one embodiment, the system 100 includes one or more clients 114 connected to one or more computer 112 through one or more computer networks 116. A client 114 may be a host, a server, a storage controller of a SAN, a workstation, a personal computer, a laptop computer, a handheld computer, a supercomputer, a computer cluster, a network switch, router, or appliance, a database or storage appliance, a data acquisition or data capture system, a diagnostic system, a test system, a robot, a portable electronic device, a wireless device, or the like. The computer network 116 may include the Internet, a wide area network (“WAN”), a metropolitan area network (“MAN”), a local area network (“LAN”), a token ring, a wireless network, a fiber channel network, a SAN, network attached storage (“NAS”), ESCON, or the like, or any combination of networks. The computer network 116 may also include a network from the IEEE 802 family of network technologies, such Ethernet, token ring, WiFi, WiMax, and the like.

The computer network 116 may include servers, switches, routers, cabling, radios, and other equipment used to facilitate networking computers 112 and clients 114. In one embodiment, the system 100 includes multiple computers 112 that communicate as peers over a computer network 116. In another embodiment, the system 100 includes multiple solid-state storage devices 102 that communicate as peers over a computer network 116. One of skill in the art will recognize other computer networks 116 comprising one or more computer networks 116 and related equipment with single or redundant connection between one or more clients 114 or other computer with one or more solid-state storage devices 102 or one or more solid-state storage devices 102 connected to one or more computers 112. In one embodiment, the system 100 includes two or more solid-state storage devices 102 connected through the computer network 118 to a client 116 without a computer 112.

Storage Controller-Managed Objects

FIG. 1B is a schematic block diagram illustrating one embodiment of a system 101 for object management in a storage device in accordance with the present invention. The system 101 includes one or more storage device 150, each with a storage controller 152 and one or more data storage devices 154, and one or more requesting devices 155. The storage devices 152 are networked together and coupled to one or more requesting devices 155. The requesting device 155 sends object requests to a storage device 150 a. An object request may be a request to create an object, a request to write data to an object, a request to read data from an object, a request to delete an object, a request to checkpoint an object, a request to copy an object, and the like. One of skill in the art will recognize other object requests.

In one embodiment, the storage controller 152 and data storage device 154 are separate devices. In another embodiment, the storage controller 152 and data storage device 154 are integrated into one storage device 150. In another embodiment, a data storage device 154 is a solid-state storage 110 and the storage controller is a solid-state storage device controller 202. In other embodiments, a data storage device 154 may be a hard disk drive, an optical drive, tape storage, or the like. In another embodiment, a storage device 150 may include two or more data storage devices 154 of different types.

In one embodiment, the data storage device 154 is a solid-state storage 110 and is arranged as an array of solid-state storage elements 216, 218, 220. In another embodiment, the solid-state storage 110 is arranged in two or more banks 214 a-n. Solid-state storage 110 is described in more detail below with respect to FIG. 2B.

The storage devices 150 a-n may be networked together and act as a distributed storage device. The storage device 150 a coupled to the requesting device 155 controls object requests to the distributed storage device. In one embodiment, the storage devices 150 and associated storage controllers 152 manage objects and appear to the requesting device(s) 155 as a distributed object file system. In this context, a parallel object file system is an example of a type of distributed object file system. In another embodiment, the storage devices 150 and associated storage controllers 152 manage objects and appear to the requesting device(s) 155 as distributed object file servers. In this context, a parallel object file server is an example of a type of distributed object file server. In these and other embodiments the requesting device 155 may exclusively manage objects or participate in managing objects in conjunction with storage devices 150; this typically does not limit the ability of storage devices 150 to fully manage objects for other clients 114. In the degenerate case, each distributed storage device, distributed object file system and distributed object file server can operate independently as a single device. The networked storage devices 150 a-n may operate as distributed storage devices, distributed object file systems, distributed object file servers, and any combination thereof having images of one or more of these capabilities configured for one or more requesting devices 155. Fore example, the storage devices 150 may be configured to operate as distributed storage devices for a first requesting device 155 a, while operating as distributed storage devices and distributed object file systems for requesting devices 155 b. Where the system 101 includes one storage device 150 a, the storage controller 152 a of the storage device 150 a manages objects may appear to the requesting device(s) 155 as an object file system or an object file server.

In one embodiment where the storage devices 150 are networked together as a distributed storage device, the storage devices 150 serve as a redundant array of independent drives (“RAID”) managed by one or more distributed storage controllers 152. For example, a request to write a data segment of an object results in the data segment being stripped across the data storage devices 154 a-n with a parity stripe, depending upon the RAID level. One benefit of such an arrangement is that such an object management system may continue to be available when a single storage device 150 has a failure, whether of the storage controller 152, the data storage device 154, or other components of storage device 150.

When redundant networks are used to interconnect the storage devices 150 and requesting devices 155, the object management system may continue to be available in the presence of network failures as long as one of the networks remains operational. A system 101 with a single storage device 150 a may also include multiple data storage devices 154 a and the storage controller 152 a of the storage device 150 a may act as a RAID controller and stripe the data segment across the data storage devices 154 a of the storage device 150 a and may include a parity stripe, depending upon the RAID level.

In one embodiment, where the one or more storage devices 150 a-n are solid-state storage devices 102 with a solid-state storage device controller 202 and solid-state storage 110, the solid-state storage device(s) 102 may be configured in a DIMM configuration, daughter card, micro-module, etc. and reside in a computer 112. The computer 112 may be a server or similar device with the solid-state storage devices 102 networked together and acting as distributed RAID controllers. Beneficially, the storage devices 102 may be connected using PCI-e, PCIe-AS, Infiniband or other high-performance bus, switched bus, networked bus, or network and may provide a very compact, high performance RAID storage system with single or distributed solid-state storage controllers 202 autonomously striping a data segment across solid-state storage 110 a-n.

In one embodiment, the same network used by the requesting device 155 to communicate with storage devices 150 may be used by the peer storage device 150 a to communicate with peer storage devices 150 b-n to accomplish RAID functionality. In another embodiment, a separate network may be used between the storage devices 150 for the purpose of RAIDing. In another embodiment, the requesting devices 155 may participate in the RAIDing process by sending redundant requests to the storage devices 150. For example, requesting device 155 may send a first object write request to a first storage device 150 a and a second object write request with the same data segment to a second storage device 150 b to achieve simple mirroring.

With the ability for object handling within the storage device(s) 102, the storage controller(s) 152 uniquely have the ability to store one data segment or object using one RAID level while another data segment or object is stored using a different RAID level or without RAID striping. These multiple RAID groupings may be associated with multiple partitions within the storage devices 150. RAID 0, RAID 1, RAID5, RAID6 and composite RAID types 10, 50, 60, can be supported simultaneously across a variety of RAID groups comprising data storage devices 154 a-n. One skilled in the art will recognize other RAID types and configurations that may also be simultaneously supported.

Also, because the storage controller(s) 152 operate autonomously as RAID controllers, the RAID controllers can perform progressive RAIDing and can transform objects or portions of objects striped across data storage devices 154 with one RAID level to another RAID level without the requesting device 155 being affected, participating or even detecting the change in RAID levels. In the preferred embodiment, progressing the RAID configuration from one level to another level may be accomplished autonomously on an object or even a packet bases and is initiated by a distributed RAID control module operating in one of the storage devices 150 or the storage controllers 152. Typically, RAID progression will be from a higher performance and lower efficiency storage configuration such as RAID1 to a lower performance and higher storage efficiency configuration such as RAID5 where the transformation is dynamically initiated based on the frequency of access. But, one can see that progressing the configuration from RAID5 to RAID1 is also possible. Other processes for initiating RAID progression may be configured or requested from clients or external agents such a storage system management server request. One of skill in the art will recognize other features and benefits of a storage device 102 with a storage controller 152 that autonomously manages objects.

Solid-State Storage Device with In-Server SAN

FIG. 1C is a schematic block diagram illustrating one embodiment of a system 103 for an in-server storage area network (“SAN”) in accordance with the present invention. The system 103 includes a computer 112 typically configured as a server (“server 112”). Each server 112 includes one or more storage devices 150 where the server 112 and storage devices 150 are each connected to a shared network interface 156. Each storage device 150 includes a storage controller 152 and corresponding data storage device 154. The system 103 includes clients 114, 114 a, 114 b that are either internal or external to the servers 112. The clients 114, 114 a, 114 b may communicate with each server 112 and each storage device 150 through over one or more computer networks 116, which are substantially similar to those described above.

The storage device 150 includes a DAS module 158, a NAS module 160, a storage communication module 162, an in-server SAN module 164, a common interface module 166, a proxy module 170, a virtual bus module 172, a front-end RAID module 174, and back-end RAID module 176, which are described below. While the modules 158-176 are shown in a storage device 150, all or a portion of each module 158-176 may be in the storage device 150, server 112, storage controller 152, or other location.

A server 112, as used in conjunction with in-server SAN, is a computer functioning as a server. The server 112 includes at least one server function, such as a file server function, but may also include other server functions as well. The servers 112 may be part of a server farm and may service other clients 114. In other embodiments, the server 112 may also be a personal computer, a workstation, or other computer that houses storage devices 150. A server 112 may access one or more storage devices 150 in the server 112 as direct attached storage (“DAS”), SAN attached storage or network attached storage (“NAS”). Storage controllers 150 participating in an in-server SAN or NAS may be internal or external to the server 112.

In one embodiment, the in-server SAN apparatus includes a DAS module 158 that configures at least a portion of the at least one data storage device 154 controlled by a storage controller 152 in a server 112 as a DAS device attached to the server 112 for servicing storage requests from at least one client 114 to the server 112. In one embodiment, a first data storage device 154 a is configured as a DAS to the first server 112 a while also being configured as an in-server SAN storage device to the first server 112 a. In another embodiment, the first data storage device 154 a is partitioned so one partition is a DAS and the other is an in-server SAN. In another embodiment, at least a portion of storage space within the first data storage device 154 a is configured as a DAS to the first server 112 a and the same portion of storage space on the first data storage device 154 a is configured as an in-server SAN to the first server 112 a.

In another embodiment, the in-server SAN apparatus includes a NAS module 160 that configures a storage controller 152 as a NAS device for at least one client 114 and services file requests from the client 114. The storage controller 152 may be also configured as an in-server SAN device for the first server 112 a. The storage devices 150 may directly connect to the computer network 116 through the shared network interface 156 independent from the server 112 in which the storage device 150 resides.

In one elemental form, an apparatus for in-server SAN includes a first storage controller 152 a within a first server 112 a where the first storage controller 152 a controls at least one storage device 154 a. The first server 112 a includes a network interface 156 shared by the first server 112 a and the first storage controller 152 a. The in-server SAN apparatus includes a storage communication module 162 that facilitates communication between the first storage controller 152 a and at least one device external to the first server 112 a such that the communication between the first storage controller 152 a and the external device is independent from the first server 112 a. The storage communication module 162 may allow the first storage controller 152 a to independently access the network interface 156 a for external communication. In one embodiment, the storage communication module 162 accesses a switch in the network interface 156 a to direct network traffic between the first storage controller 152 a and external devices.

The in-server SAN apparatus also includes an in-server SAN module 164 that services a storage request using one or both of a network protocol and a bus protocol. The in-server SAN module 164 services the storage request independent from the first server 112 a and the service request is received from an internal or external client 114, 114 a.

In one embodiment, the device external to the first server 112 a is a second storage controller 152 b. The second storage controller 152 b controls at least one data storage device 154 b. The in-server SAN module 164 services the storage request using communication through the network interface 156 a and between the first and second storage controllers 152 a, 152 b independent of the first server 112 a. The second storage controller 152 b may be within a second server 112 b or within some other device.

In another embodiment, the device external to the first server 112 a is a client 114 and the storage request originates with the external client 114 where the first storage controller is configured as at least part of a SAN and the in-server SAN module 164 services the storage request through the network interface 156 a independent of the first server 112 a. The external client 114 may be in the second server 112 b or may be external to the second server 112 b. In one embodiment, the in-server SAN module 164 can service storage requests from the external client 114 even when the first server 112 a is unavailable.

In another embodiment, the client 114 a originating the storage request is internal to the first server 112 a where the first storage controller 152 a is configured as at least part of a SAN and the in-server SAN module 164 services the storage request through one or more of the network interface 156 a and system bus.

Traditional SAN configurations allow a storage device remote from a server 112 to be accessed as if the storage device resides within the server 112 as direct attached storage (“DAS”) so that the storage device appears as a block storage device. Typically, a storage device connected as a SAN requires a SAN protocol, such as fiber channel, Internet small computer system interface (“iSCSI”), HyperSCSI, Fiber Connectivity (“FICON”), Advanced Technology Attachment (“ATA”) over Ethernet, etc. In-server SAN includes a storage controller 152 inside a server 112 while still allowing network connection between the storage controller 152 a and a remote storage controller 152 b or an external client 114 using a network protocol and/or a bus protocol.

Typically, SAN protocols are a form of network protocol and more network protocols are emerging, such as Infiniband that would allow a storage controller 150 a, and associated data storage devices 154 a, to be configured as a SAN and communicate with an external client 114 or second storage controller 152 b. In another example, a first storage controller 152 a may communicate with an external client 114 or second storage controller 152 b using Ethernet.

A storage controller 152 may communicate over a bus with internal storage controllers 152 or clients 114 a. For example, a storage controller 152 may communicate over a bus using PCI-e that may support PCI Express Input/Output Virtualization (“PCIe-IOV”). Other emerging bus protocols allow a system bus to extend outside a computer or server 112 and would allow a storage controller 152 a to be configured as a SAN. One such bus protocol is PCIe-AS. The present invention is not limited to simply SAN protocols, but may also take advantage of the emerging network and bus protocols to service storage requests. An external device, either in the form of a client 114 or external storage controller 152 b, may communicate over an extended system bus or a computer network 116. A storage request, as used herein, includes requests to write data, read data, erase data, query data, etc. and may include object data, metadata, and management requests as well as block data requests.

A traditional server 112 typically has a root complex that controls access to devices within the server 112. Typically, this root complex of the server 112 owns the network interface 156 such so any communication through the network interface 156 is controlled by the server 112. However, in the preferred embodiment of the in-server SAN apparatus, the storage controller 152 is able to access the network interface 156 independently so that clients 114 may communicate directly with one or more of the storage controllers 152 a in the first server 112 a forming a SAN or so that one or more first storage controllers 152 a may be networked together with a second storage controller 152 b or other remote storage controllers 152 to form a SAN. In the preferred embodiment, devices remote from the first server 112 a may access the first server 112 a or the first storage controller 152 a through a single, shared network address. In one embodiment, the in-server SAN apparatus includes a common interface module 166 that configures the network interface 156, the storage controller 152, and the server 112 such that the server 112 and the storage controller 152 are accessible using a shared network address.

In other embodiments, the server 112 includes two or more network interfaces 156. For example, the server 112 may communicate over one network interface 156 while the storage device 150 may communicate over another interface. In another example, the server 112 includes multiple storage devices 150, each with a network interface 156. One of skill in the art will recognize other configurations of a server 112 with one or more storage devices 150 and one or more network interfaces 156 where one or more of the storage devices 150 access a network interface 156 independent of the server 112. One of skill in the art will also recognize how these various configurations may be extended to support network redundancy and improve availability.

Advantageously, the in-server SAN apparatus eliminates much of the complexity and expense of a traditional SAN. For example, a typical SAN requires servers 112 with external storage controllers 152 and associated data storage devices 154. This takes up additional space in a rack and requires cabling, switches, etc. The cabling, switching, another other overhead required to configure a traditional SAN take space, degrade bandwidth, and are expensive. The in-server SAN apparatus allows the storage controllers 152 and associated storage 154 to fit in a server 112 form factor, thus reducing required space and costing less. In-server SAN also allows connection using relatively fast communication over internal and external high-speed data buses.

In one embodiment, the storage device 150 is a solid-state storage device 102, the storage controller 152 is a solid-state storage controller 104, and the data storage device 154 is a solid-state storage 110. This embodiment is advantageous because of the speed of solid-state storage device 102 as described herein. In addition, the solid-state storage device 102 may be configured in a DIMM which may conveniently fit in a server 112 and require a small amount of space.

The one or more internal clients 114 a in the server 112 may also connect to the computer network 116 through the server's network interface 156 and the client's connection is typically controlled by the server 112. This has several advantages. Clients 114 a may locally and remotely access the storage devices 150 directly and may initiate a local or remote direct memory access (“DMA,” “RDMA”) data transfer between the memory of a client 114 a and a storage device 150.

In another embodiment, clients 114, 114 a within or external to a server 112 may act as file servers to clients 114 through one or more networks 116 while utilizing locally attached storage devices 150 as DAS devices, network attached storage devices 150, network attached solid-state storages 102 devices participating as part of in-server SANs, external SANs, and hybrid SANs. A storage device 150 may participate in a DAS, in-server-SAN, SAN, NAS, etc, simultaneously and in any combination. Additionally, each storage device 150 may be partitioned in such a way that a first partition makes the storage device 150 available as a DAS, a second partition makes the storage device 150 available as an element in an in-server-SAN, a third partition makes the storage device 150 available as a NAS, a fourth partition makes the storage device 150 available as an element in a SAN, etc. Similarly, the storage device 150 may be partitioned consistent with security and access control requirements. One of skill in the art will recognize that any number of combinations and permutations of storage devices, virtual storage devices, storage networks, virtual storage networks, private storage, shared storage, parallel file systems, parallel object file systems, block storage devices, object storage devices, storage appliances, network appliances, and the like may be constructed and supported.

In addition, by directly connecting to the computer network 116, the storage devices 150 can communicate with each other and can act as an in-server SAN. Clients 114 a in the servers 112 and clients 114 connected through the computer network 116 may access the storage devices 150 as a SAN. By moving the storage devices 150 into the servers 112 and having the ability to configure the storage devices 150 as a SAN, the server 112/storage device 150 combination eliminates the need in conventional SANs for dedicated storage controllers, fiber channel networks, and other equipment. The in-server SAN system 103 has the advantage of enabling the storage device 150 to share common resources such as power, cooling, management, and physical space with the client 114 and computer 112. For example, storage devices 150 may fill empty slots of servers 112 and provide all the performance capabilities, reliability and availability of a SAN or NAS. One of skill in the art will recognize other features and benefits of an in-server SAN system 103.

In another configuration, multiple in-server-SAN storage devices 150 a are collocated within a single server 112 a infrastructure. In one embodiment, the server 112 a is comprised of one or more internal bladed server clients 114 a interconnected using PCI-express IOV without an external network interface 156, external client 114, 114 b or external storages device 150 b.

In addition, in-server SAN storage device 150 may communicate through one or more computer networks 116 with peer storage devices 150 that are located in a computer 112 (per FIG. 1A), or are connected directly to the computer network 116 without a computer 112 to form a hybrid SAN which has all the capabilities of both SAN and in-server SAN. This flexibility has the benefit of simplifying extensibility and migration between a variety of possible solid-state storage network implementations. One skilled in the art will recognize other combinations, configurations, implementations, and architectures for locating and interconnecting solid-state controllers 104.

Where the network interface 156 a can be controlled by only one agent operating within the server 112 a, a link setup module 168 operating within that agent can set up communication paths between internal clients 114 a and storage devices 150 a/first storage controllers 152 a through network interface 156 a to external storage devices 150 b and clients 114, 114 b. In a preferred embodiment, once the communication path is established, the individual internal storage devices 150 a and internal clients 114 a are able to establish and manage their own command queues and transfer both commands and data through network interface 156 a to external storage devices 150 b and clients 114, 114 b in either direction, directly and through RDMA independent of the proxy or agent controlling the network interface 156 a. In one embodiment, the link setup module 168 establishes the communication links during an initialization process, such as a startup or initialization of hardware.

In another embodiment, a proxy module 170 directs at least a portion of commands used in servicing a storage request through the first server 112 a while at least data, and possibly other commands, associated with the storage request are communicated between the first storage controller and the external storage device independent of the first server. In another embodiment, the proxy module 170 forwards commands or data in behalf of the internal storage devices 150 a and clients 114 a.

In one embodiment, the first server 112 a includes one or more servers within the first server 112 a and includes a virtual bus module 172 that allows the one or more servers in the first server 112 a to independently access one or more storage controllers 152 a through separate virtual buses. The virtual buses may be established using an advanced bus protocol such as PCIe-IOV. Network interfaces 156 a supporting IOV may allow the one or more servers and the one or more storage controllers to independently control the one or more network interfaces 156 a.

In various embodiments, the in-server SAN apparatus allows two or more storage devices 150 to be configured in a RAID. In one embodiment, the in-server SAN apparatus includes a front-end RAID module 174 that configures two or more storage controllers 152 as a RAID. Where a storage request from a client 114, 114 a includes a request to store data, the front-end RAID module 174 services the storage request by writing the data to the RAID consistent with the particular implemented RAID level. A second storage controller 152 may be located either in the first server 112 a or external to the first server 112 a. The front-end RAID module 174 allows RAIDing of storage controllers 152 such that the storage controllers 152 are visible to the client 114, 114 a sending the storage request. This allows striping and parity information to be managed by a storage controller 152 designated as master or by the client 114, 114 a.

In another embodiment, the in-server SAN apparatus includes a back-end RAID module 176 that configures two or more data storage devices 154 controlled by a storage controller as a RAID. Where the storage request from the client comprises a request to store data, the back-end RAID module 176 services the storage request by writing the data to the RAID consistent with an implemented RAID level such that the storage devices 154 configured as a RAID are accessed by the client 114, 114 a as a single data storage device 154 controlled by the first storage controller 152. This RAID implementation allows RAIDing of the data storage devices 154 controlled by a storage controller 152 in a way that the RAIDing is transparent to any client 114, 114 a accessing the data storage devices 154. In another embodiment, both front-end RAID and back-end RAID are implemented to have multi-level RAID. One of skill in the art will recognize other ways to RAID the storage devices 152 consistent with the solid-state storage controller 104 and associated solid-state storage 110 described herein.

Apparatus for Storage Controller-Managed Objects

FIG. 2A is a schematic block diagram illustrating one embodiment of an apparatus 200 for object management in a storage device in accordance with the present invention. The apparatus 200 includes a storage controller 152 with an object request receiver module 260, a parsing module 262, a command execution module 264, an object index module 266, an object request queuing module 268, a packetizer 302 with a messages module 270, and an object index reconstruction module 272, which are described below.

The storage controller 152 is substantially similar to the storage controller 152 described in relation to the system 102 of FIG. 1B and may be a solid-state storage device controller 202 described in relation to FIG. 2. The apparatus 200 includes an object request receiver module 260 that receives an object request from one or more requesting devices 155. For example, for a store object data request, the storage controller 152 stores the data segment as a data packet in a data storage device 154 coupled to the storage controller 152. The object request is typically directed at a data segment stored or to be stored in one or more object data packets for an object managed by the storage controller. The object request may request that the storage controller 152 create an object to be later filled with data through later object request which may utilize a local or remote direct memory access (“DMA,” “RDMA”) transfer.

In one embodiment, the object request is a write request to write all or part of an object to a previously created object. In one example, the write request is for a data segment of an object. The other data segments of the object may be written to the storage device 150 or to other storage devices 152. In another example, the write request is for an entire object. In another example, the object request is to read data from a data segment managed by the storage controller 152. In yet another embodiment, the object request is a delete request to delete a data segment or object.

Advantageously, the storage controller 152 can accept write requests that do more than write a new object or append data to an existing object. For example, a write request received by the object request receiver module 260 may include a request to add data ahead of data stored by the storage controller 152, to insert data into the stored data, or to replace a segment of data. The object index maintained by the storage controller 152 provides the flexibility required for these complex write operations that is not available in other storage controllers, but is currently available only outside of storage controllers in file systems of servers and other computers.

The apparatus 200 includes a parsing module 262 that parses the object request into one or more commands. Typically, the parsing module 262 parses the object request into one or more buffers. For example, one or more commands in the object request may be parsed into a command buffer. Typically the parsing module 262 prepares an object request so that the information in the object request can be understood and executed by the storage controller 152. One of skill in the art will recognize other functions of a parsing module 262 that parses an object request into one or more commands.

The apparatus 200 includes a command execution module 264 that executes the command(s) parsed from the object request. In one embodiment, the command execution module 264 executes one command. In another embodiment, the command execution module 264 executes multiple commands. Typically, the command execution module 264 interprets a command parsed from the object request, such as a write command, and then creates, queues, and executes subcommands. For example, a write command parsed from an object request may direct the storage controller 152 to store multiple data segments. The object request may also include required attributes such as encryption, compression, etc. The command execution module 264 may direct the storage controller 152 to compress the data segments, encrypt the data segments, create one or more data packets and associated headers for each data packet, encrypt the data packets with a media encryption key, add error correcting code, and store the data packets a specific location. Storing the data packets at a specific location and other subcommands may also be broken down into other lower level subcommands. One of skill in the art will recognize other ways that the command execution module 264 can execute one or more commands parsed from an object request.

The apparatus 200 includes an object index module 266 that creates an object entry in an object index in response to the storage controller 152 creating an object or storing the data segment of the object. Typically, the storage controller 152 creates a data packet from the data segment and the location of where the data packet is stored is assigned at the time the data segment is stored. Object metadata received with a data segment or as part of an object request may be stored in a similar way.

The object index module 266 creates an object entry into an object index at the time the data packet is stored and the physical address of the data packet is assigned. The object entry includes a mapping between a logical identifier of the object and one or more physical addresses corresponding to where the storage controller 152 stored one or more data packets and any object metadata packets. In another embodiment, the entry in the object index is created before the data packets of the object are stored. For example, if the storage controller 152 determines a physical address of where the data packets are to be stored earlier, the object index module 266 may create the entry in the object index earlier.

Typically, when an object request or group of object requests results in an object or data segment being modified, possibly during a read-modify-write operation, the object index module 266 updates an entry in the object index corresponding the modified object. In one embodiment, the object index creates a new object and a new entry in the object index for the modified object. Typically, where only a portion of an object is modified, the object includes modified data packets and some data packets that remain unchanged. In this case, the new entry includes a mapping to the unchanged data packets as where they were originally written and to the modified objects written to a new location.

In another embodiment, where the object request receiver module 260 receives an object request that includes a command that erases a data block or other object elements, the storage controller 152 may store at least one packet such as an erase packet that includes information including a reference to the object, relationship to the object, and the size of the data block erased. Additionally, it may further indicate that the erased object elements are filled with zeros. Thus, the erase object request can be used to emulate actual memory or storage that is erased and actually has a portion of the appropriate memory/storage actually stored with zeros in the cells of the memory/storage.

Beneficially, creating an object index with entries indicating mapping between data segments and metadata of an object allows the storage controller 152 to autonomously handle and manage objects. This capability allows a great amount of flexibility for storing data in the storage device 150. Once the index entry for the object is created, subsequent object requests regarding the object can be serviced efficiently by the storage controller 152.

In one embodiment, the storage controller 152 includes an object request queuing module that queues one or more object requests received by the object request receiver module 260 prior to parsing by the parsing module 262. The object request queuing module 268 allows flexibility between when an object request is received and when it is executed.

In another embodiment, the storage controller 152 includes a packetizer 302 that creates one or more data packets from the one or more data segments where the data packets are sized for storage in the data storage device 154. The packetizer 302 is described below in more detail with respect to FIG. 3. The packetizer 302 includes, in one embodiment, a messages module 270 that creates a header for each packet. The header includes a packet identifier and a packet length. The packet identifier relates the packet to the object for which the packet was formed.

In one embodiment, each packet includes a packet identifier that is self-contained in that the packet identifier contains adequate information to identify the object and relationship within the object of the object elements contained within the packet. However, a more efficient preferred embodiment is to store packets in containers.

A container is a data construct that facilitates more efficient storage of packets and helps establish relationships between an object and data packets, metadata packets, and other packets related to the object that are stored within the container. Note that the storage controller 152 typically treats object metadata received as part of an object and data segments in a similar manner. Typically “packet” may refer to a data packet comprising data, a metadata packet comprising metadata, or another packet of another packet type. An object may be stored in one or more containers and a container typically includes packets for no more than one unique object. An object may be distributed between multiple containers. Typically a container is stored within a single logical erase block (storage division) and is typically never split between logical erase blocks.

A container, in one example, may be split between two or more logical/virtual pages. A container is identified by a container label that associates that container with an object. A container may contain zero to many packets and the packets within a container are typically from one object. A packet may be of many object element types, including object attribute elements, object data elements, object index elements, and the like. Hybrid packets may be created that include more than one object element type. Each packet may contain zero to many elements of the same element type. Each packet within a container typically contains a unique identifier that identifies the relationship to the object.

Each packet is associated with one container. In a preferred embodiment, containers are limited to an erase block so that at or near the beginning of each erase block a container packet can be found. This helps limit data loss to an erase block with a corrupted packet header. In this embodiment, if the object index is unavailable and a packet header within the erase block is corrupted, the contents from the corrupted packet header to the end of the erase block may be lost because there is possibly no reliable mechanism to determine the location of subsequent packets. In another embodiment, a more reliable approach is to have a container limited to a page boundary. This embodiment requires more header overhead. In another embodiment, containers can flow across page and erase block boundaries. This requires less header overhead but a larger portion of data may be lost if a packet header is corrupted. For these several embodiments it is expected that some type of RAID is used to further ensure data integrity.

In one embodiment, the apparatus 200 includes an object index reconstruction module 272 that that reconstructs the entries in the object index using information from packet headers stored in the data storage device 154. In one embodiment, the object index reconstruction module 272 reconstructs the entries of the object index by reading headers to determine the object to which each packet belongs and sequence information to determine where in the object the data or metadata belongs. The object index reconstruction module 272 uses physical address information for each packet and timestamp or sequence information to create a mapping between the physical locations of the packets and the object identifier and data segment sequence. Timestamp or sequence information is used by the object index reconstruction module 272 to replay the sequence of changes made to the index and thereby typically reestablish the most recent state.

In another embodiment, the object index reconstruction module 272 locates packets using packet header information along with container packet information to identify physical locations of the packets, object identifier, and sequence number of each packet to reconstruct entries in the object index. In one embodiment, erase blocks are time stamped or given a sequence number as packets are written and the timestamp or sequence information of an erase block is used along with information gathered from container headers and packet headers to reconstruct the object index. In another embodiment, timestamp or sequence information is written to an erase block when the erase block is recovered.

Where the object index is stored in volatile memory, an error, loss of power, or other problem causing the storage controller 152 to shut down without saving the object index could be a problem if the object index cannot be reconstructed. The object index reconstruction module 272 allows the object index to be stored in volatile memory allowing the advantages of volatile memory, such as fast access. The object index reconstruction module 272 allows quick reconstruction of the object index autonomously without dependence on a device external to the storage device 150.

In one embodiment, the object index in volatile memory is stored periodically in a data storage device 154. In a particular example, the object index, or “index metadata,” is stored periodically in a solid-state storage 110. In another embodiment, the index metadata is stored in a solid-state storage 110 n separate from solid-state storage 110 a-110 n-1 storing packets. The index metadata is managed independently from data and object metadata transmitted from a requesting device 155 and managed by the storage controller 152/solid-state storage device controller 202. Managing and storing index metadata separate from other data and metadata from an object allows efficient data flow without the storage controller 152/solid-state storage device controller 202 unnecessarily processing object metadata.

In one embodiment, where an object request received by the object request receiver module 260 includes a write request, the storage controller 152 receives one or more data segments of an object from memory of a requesting device 155 as a local or remote direct memory access (“DMA,” “RDMA”) operation. In a preferred example, the storage controller 152 pulls data from the memory of the requesting device 155 in one or more DMA or RDMA operations. In another example, the requesting device 155 pushes the data segment(s) to the storage controller 152 in one or more DMA or RDMA operations. In another embodiment, where the object request includes a read request, the storage controller 152 transmits one or more data segments of an object to the memory of the requesting device 155 in one or more DMA or RDMA operations. In a preferred example, the storage controller 152 pushes data to the memory of the requesting device 155 in one or more DMA or RDMA operations. In another example, the requesting device 155 pulls data from the storage controller 152 in one or more DMA or RDMA operations. In another example, the storage controller 152 pulls object command request sets from the memory of the requesting device 155 in one or more DMA or RDMA operations. In another example, the requesting device 155 pushes object command request sets to the storage controller 152 in one or more DMA or RDMA operations.

In one embodiment, the storage controller 152 emulates block storage and an object communicated between the requesting device 155 and the storage controller 152 comprises one or more data blocks. In one embodiment, the requesting device 155 includes a driver so that the storage device 150 appears as a block storage device. For example, the requesting device 152 may send a block of data of a certain size along with a physical address of where the requesting device 155 wants the data block stored. The storage controller 152 receives the data block and uses the physical block address transmitted with the data block or a transformation of the physical block address as an object identifier. The storage controller 156 then stores the data block as an object or data segment of an object by packetizing the data block and storing the data block at will. The object index module 266 then creates an entry in the object index using the physical block-based object identifier and the actual physical location where the storage controller 152 stored the data packets comprising the data from the data block.

In another embodiment, the storage controller 152 emulates block storage by accepting block objects. A block object may include one or more data blocks in a block structure. In one embodiment, the storage controller 152 treats the block object as any other object. In another embodiment, an object may represent an entire block device, partition of a block device, or some other logical or physical sub-element of a block device including a track, sector, channel, and the like. Of particular note is the ability to remap a block device RAID group to an object supporting a different RAID construction such as progressive RAID. One skilled in the art will recognize other mappings of traditional or future block devices to objects.

Solid-State Storage Device

FIG. 2B is a schematic block diagram illustrating one embodiment 201 of a solid-state storage device controller 202 that includes a write data pipeline 106 and a read data pipeline 108 in a solid-state storage device 102 in accordance with the present invention. The solid-state storage device controller 202 may include a number of solid-state storage controllers 0-N 104 a-n, each controlling solid-state storage 110. In the depicted embodiment, two solid-state controllers are shown: solid-state controller 0 104 a and solid-state storage controller N 104 n, and each controls solid-state storage 110 a-n. In the depicted embodiment, solid-state storage controller 0 104 a controls a data channel so that the attached solid-state storage 110 a stores data. Solid-state storage controller N 104 n controls an index metadata channel associated with the stored data and the associated solid-state storage 110 n stores index metadata. In an alternate embodiment, the solid-state storage device controller 202 includes a single solid-state controller 104 a with a single solid-state storage 110 a. In another embodiment, there are a plurality of solid-state storage controllers 104 a-n and associated solid-state storage 110 a-n. In one embodiment, one or more solid state controllers 104 a-104 n-1, coupled to their associated solid-state storage 110 a-110 n-1, control data while at least one solid-state storage controller 104 n, coupled to its associated solid-state storage 110 n, controls index metadata.

In one embodiment, at least one solid-state controller 104 is field-programmable gate array (“FPGA”) and controller functions are programmed into the FPGA. In a particular embodiment, the FPGA is a Xilinx® FPGA. In another embodiment, the solid-state storage controller 104 comprises components specifically designed as a solid-state storage controller 104, such as an application-specific integrated circuit (“ASIC”) or custom logic solution. Each solid-state storage controller 104 typically includes a write data pipeline 106 and a read data pipeline 108, which are describe further in relation to FIG. 3. In another embodiment, at least one solid-state storage controller 104 is made up of a combination FPGA, ASIC, and custom logic components.

Solid-State Storage

The solid state storage 110 is an array of non-volatile solid-state storage elements 216, 218, 220, arranged in banks 214, and accessed in parallel through a bi-directional storage input/output (“I/O”) bus 210. The storage I/O bus 210, in one embodiment, is capable of unidirectional communication at any one time. For example, when data is being written to the solid-state storage 110, data cannot be read from the solid-state storage 110. In another embodiment, data can flow both directions simultaneously. However bi-directional, as used herein with respect to a data bus, refers to a data pathway that can have data flowing in only one direction at a time, but when data flowing one direction on the bi-directional data bus is stopped, data can flow in the opposite direction on the bi-directional data bus.

A solid-state storage element (e.g. SSS 0.0 216 a) is typically configured as a chip (a package of one or more dies) or a die on a circuit board. As depicted, a solid-state storage element (e.g. 216 a) operates independently or semi-independently of other solid-state storage elements (e.g. 218 a) even if these several elements are packaged together in a chip package, a stack of chip packages, or some other package element. As depicted, a column of solid-state storage elements 216, 218, 220 is designated as a bank 214. As depicted, there may be “n” banks 214 a-n and “m” solid-state storage elements 216 a-m, 218 a-m, 220 a-m per bank in an array of n×m solid-state storage elements 216, 218, 220 in a solid-state storage 110. In one embodiment, a solid-state storage 110 a includes twenty solid-state storage elements 216, 218, 220 per bank 214 with eight banks 214 and a solid-state storage 110 n includes 2 solid-state storage elements 216, 218 per bank 214 with one bank 214. In one embodiment, each solid-state storage element 216, 218, 220 is comprised of a single-level cell (“SLC”) devices. In another embodiment, each solid-state storage element 216,218,220 is comprised of multi-level cell (“MLC”) devices.

In one embodiment, solid-state storage elements for multiple banks that share a common storage I/O bus 210 a row (e.g. 216 b, 218 b, 220 b) are packaged together. In one embodiment, a solid-state storage element 216, 218, 220 may have one or more dies per chip with one or more chips stacked vertically and each die may be accessed independently. In another embodiment, a solid-state storage element (e.g. SSS 0.0 216 a) may have one or more virtual dies per die and one or more dies per chip and one or more chips stacked vertically and each virtual die may be accessed independently. In another embodiment, a solid-state storage element SSS 0.0 216 a may have one or more virtual dies per die and one or more dies per chip with some or all of the one or more dies stacked vertically and each virtual die may be accessed independently.

In one embodiment, two dies are stacked vertically with four stacks per group to form eight storage elements (e.g. SSS 0.0-SSS 0.8) 216 a-220 a, each in a separate bank 214 a-n. In another embodiment, 20 storage elements (e.g. SSS 0.0-SSS 20.0) 216 form a virtual bank 214 a so that each of the eight virtual banks has 20 storage elements (e.g. SSS0.0-SSS 20.8) 216, 218, 220. Data is sent to the solid-state storage 110 over the storage I/O bus 210 to all storage elements of a particular group of storage elements (SSS 0.0-SSS 0.8) 216 a, 218 a, 220 a. The storage control bus 212 a is used to select a particular bank (e.g. Bank-0 214 a) so that the data received over the storage I/O bus 210 connected to all banks 214 is written just to the selected bank 214 a.

In a preferred embodiment, the storage I/O bus 210 is comprised of one or more independent I/O buses (“IIOBa-m” comprising 210 a.a-m, 210 n.a-m) wherein the solid-state storage elements within each row share one of the independent I/O buses accesses each solid-state storage element 216, 218, 220 in parallel so that all banks 214 are accessed simultaneously. For example, one channel of the storage I/O bus 210 may access a first solid-state storage element 216 a, 218 a, 220 a of each bank 214 a-n simultaneously. A second channel of the storage I/O bus 210 may access a second solid-state storage element 216 b, 218 b, 220 b of each bank 214 a-n simultaneously. Each row of solid-state storage element 216, 218, 220 is accessed simultaneously. In one embodiment, where solid-state storage elements 216, 218, 220 are multi-level (physically stacked), all physical levels of the solid-state storage elements 216, 218, 220 are accessed simultaneously. As used herein, “simultaneously” also includes near simultaneous access where devices are accessed at slightly different intervals to avoid switching noise. Simultaneously is used in this context to be distinguished from a sequential or serial access wherein commands and/or data are sent individually one after the other.

Typically, banks 214 a-n are independently selected using the storage control bus 212. In one embodiment, a bank 214 is selected using a chip enable or chip select. Where both chip select and chip enable are available, the storage control bus 212 may select one level of a multi-level solid-state storage element 216, 218, 220. In other embodiments, other commands are used by the storage control bus 212 to individually select one level of a multi-level solid-state storage element 216, 218, 220. Solid-state storage elements 216,218, 220 may also be selected through a combination of control and of address information transmitted on storage I/O bus 210 and the storage control bus 212.

In one embodiment, each solid-state storage element 216, 218, 220 is partitioned into erase blocks and each erase block is partitioned into pages. A typical page is 2000 bytes (“2 kB”). In one example, a solid-state storage element (e.g. SSS0.0) includes two registers and can program two pages so that a two-register solid-state storage element 216, 218, 220 has a capacity of 4 kB. A bank 214 of 20 solid-state storage elements 216, 218, 220 would then have an 80 kB capacity of pages accessed with the same address going out the channels of the storage I/O bus 210.

This group of pages in a bank 214 of solid-state storage elements 216, 218, 220 of 80 kB may be called a virtual page. Similarly, an erase block of each storage element 216 a-m of a bank 214 a may be grouped to form a virtual erase block. In a preferred embodiment, an erase block of pages within a solid-state storage element 216, 218, 220 is erased when an erase command is received within a solid-state storage element 216, 218, 220. Whereas the size and number of erase blocks, pages, planes, or other logical and physical divisions within a solid-state storage element 216, 218, 220 are expected to change over time with advancements in technology, it is to be expected that many embodiments consistent with new configurations are possible and are consistent with the general description herein.

Typically, when a packet is written to a particular location within a solid-state storage element 216, 218, 220, wherein the packet is intended to be written to a location within a particular page which is specific to a of a particular erase block of a particular element of a particular bank, a physical address is sent on the storage I/O bus 210 and followed by the packet. The physical address contains enough information for the solid-state storage element 216, 218, 220 to direct the packet to the designated location within the page. Since all storage elements in a row of storage elements (e.g. SSS 0.0-SSS 0.N 216 a, 218 a, 220 a) are accessed simultaneously by the appropriate bus within the storage I/O bus 210 a.a, to reach the proper page and to avoid writing the data packet to similarly addressed pages in the row of storage elements (SSS 0.0-SSS 0.N 216 a, 218 a, 220 a), the bank 214 a that includes the solid-state storage element SSS 0.0 216 a with the correct page where the data packet is to be written is simultaneously selected by the storage control bus 212.

Similarly, a read command traveling on the storage I/O bus 212 requires a simultaneous command on the storage control bus 212 to select a single bank 214 a and the appropriate page within that bank 214 a. In a preferred embodiment, a read command reads an entire page, and because there are multiple solid-state storage elements 216, 218, 220 in parallel in a bank 214, an entire virtual page is read with a read command. However, the read command may be broken into subcommands, as will be explained below with respect to bank interleave. A virtual page may also be accessed in a write operation.

An erase block erase command may be sent out to erase an erase block over the storage I/O bus 210 with a particular erase block address to erase a particular erase block. Typically, an erase block erase command may be sent over the parallel paths of the storage I/O bus 210 to erase a virtual erase block, each with a particular erase block address to erase a particular erase block. Simultaneously a particular bank (e.g. bank-0 214 a) is selected over the storage control bus 212 to prevent erasure of similarly addressed erase blocks in all of the banks (banks 1-N 214 b-n). Other commands may also be sent to a particular location using a combination of the storage I/O bus 210 and the storage control bus 212. One of skill in the art will recognize other ways to select a particular storage location using the bi-directional storage I/O bus 210 and the storage control bus 212.

In one embodiment, packets are written sequentially to the solid-state storage 110. For example, packets are streamed to the storage write buffers of a bank 214 a of storage elements 216 and when the buffers are full, the packets are programmed to a designated virtual page. Packets then refill the storage write buffers and, when full, the packets are written to the next virtual page. The next virtual page may be in the same bank 214 a or another bank (e.g. 214 b). This process continues, virtual page after virtual page, typically until a virtual erase block is filled. In another embodiment, the streaming may continue across virtual erase block boundaries with the process continuing, virtual erase block after virtual erase block.

In a read, modify, write operation, data packets associated with the object are located and read in a read operation. Data segments of the modified object that have been modified are not written to the location from which they are read. Instead, the modified data segments are again converted to data packets and then written to the next available location in the virtual page currently being written. The object index entries for the respective data packets are modified to point to the packets that contain the modified data segments. The entry or entries in the object index for data packets associated with the same object that have not been modified will include pointers to original location of the unmodified data packets. Thus, if the original object is maintained, for example to maintain a previous version of the object, the original object will have pointers in the object index to all data packets as originally written. The new object will have pointers in the object index to some of the original data packets and pointers to the modified data packets in the virtual page that is currently being written.

In a copy operation, the object index includes an entry for the original object mapped to a number of packets stored in the solid-state storage 110. When a copy is made, a new object is created and a new entry is created in the object index mapping the new object to the original packets. The new object is also written to the solid-state storage 110 with its location mapped to the new entry in the object index. The new object packets may be used to identify the packets within the original object that are referenced in case changes have been made in the original object that have not been propagated to the copy and the object index is lost or corrupted.

Beneficially, sequentially writing packets facilitates a more even use of the solid-state storage 110 and allows the solid-storage device controller 202 to monitor storage hot spots and level usage of the various virtual pages in the solid-state storage 110. Sequentially writing packets also facilitates a powerful, efficient garbage collection system, which is described in detail below. One of skill in the art will recognize other benefits of sequential storage of data packets.

Solid-State Storage Device Controller

In various embodiments, the solid-state storage device controller 202 also includes a data bus 204, a local bus 206, a buffer controller 208, buffers 0-N 222 a-n, a master controller 224, a direct memory access (“DMA”) controller 226, a memory controller 228, a dynamic memory array 230, a static random memory array 232, a management controller 234, a management bus 236, a bridge 238 to a system bus 240, and miscellaneous logic 242, which are described below. In other embodiments, the system bus 240 is coupled to one or more network interface cards (“NICs”) 244, some of which may include remote DMA (“RDMA”) controllers 246, one or more central processing unit (“CPU”) 248, one or more external memory controllers 250 and associated external memory arrays 252, one or more storage controllers 254, peer controllers 256, and application specific processors 258, which are described below. The components 244-258 connected to the system bus 240 may be located in the computer 112 or may be other devices.

Typically the solid-state storage controller(s) 104 communicate data to the solid-state storage 110 over a storage I/O bus 210. In a typical embodiment where the solid-state storage is arranged in banks 214 and each bank 214 includes multiple storage elements 216, 218, 220 accessed in parallel, the storage I/O bus 210 is an array of busses, one for each row of storage elements 216, 218, 220 spanning the banks 214. As used herein, the term “storage I/O bus” may refer to one storage I/O bus 210 or an array of data independent busses 204. In a preferred embodiment, each storage I/O bus 210 accessing a row of storage elements (e.g. 216 a, 218 a, 220 a) may include a logical-to-physical mapping for storage divisions (e.g. erase blocks) accessed in a row of storage elements 216 a, 218 a, 220 a. This mapping allows a logical address mapped to a physical address of a storage division to be remapped to a different storage division if the first storage division fails, partially fails, is inaccessible, or has some other problem. Remapping is explained further in relation to the remapping module 314 of FIG. 3.

Data may also be communicated to the solid-state storage controller(s) 104 from a requesting device 155 through the system bus 240, bridge 238, local bus 206, buffer(s) 22, and finally over a data bus 204. The data bus 204 typically is connected to one or more buffers 222 a-n controlled with a buffer controller 208. The buffer controller 208 typically controls transfer of data from the local bus 206 to the buffers 222 and through the data bus 204 to the pipeline input buffer 306 and output buffer 330. The buffer controller 222 typically controls how data arriving from a requesting device can be temporarily stored in a buffer 222 and then transferred onto a data bus 204, or vice versa, to account for different clock domains, to prevent data collisions, etc. The buffer controller 208 typically works in conjunction with the master controller 224 to coordinate data flow. As data arrives, the data will arrive on the system bus 240, be transferred to the local bus 206 through a bridge 238.

Typically the data is transferred from the local bus 206 to one or more data buffers 222 as directed by the master controller 224 and the buffer controller 208. The data then flows out of the buffer(s) 222 to the data bus 204, through a solid-state controller 104, and on to the solid-state storage 110 such as NAND flash or other storage media. In a preferred embodiment, data and associated out-of-band metadata (“object metadata”) arriving with the data is communicated using one or more data channels comprising one or more solid-state storage controllers 104 a-104 n-1 and associated solid-state storage 110 a-110 n-1 while at least one channel (solid-state storage controller 104 n, solid-state storage 110 n) is dedicated to in-band metadata, such as index information and other metadata generated internally to the solid-state storage device 102.

The local bus 206 is typically a bidirectional bus or set of busses that allows for communication of data and commands between devices internal to the solid-state storage device controller 202 and between devices internal to the solid-state storage device 102 and devices 244-258 connected to the system bus 240. The bridge 238 facilitates communication between the local bus 206 and system bus 240. One of skill in the art will recognize other embodiments such as ring structures or switched star configurations and functions of buses 240, 206, 204, 210 and bridges 238.

The system bus 240 is typically a bus of a computer 112 or other device in which the solid-state storage device 102 is installed or connected. In one embodiment, the system bus 240 may be a PCI-e bus, a Serial Advanced Technology Attachment (“serial ATA”) bus, parallel ATA, or the like. In another embodiment, the system bus 240 is an external bus such as small computer system interface (“SCSI”), FireWire, Fiber Channel, USB, PCIe-AS, or the like. The solid-state storage device 102 may be packaged to fit internally to a device or as an externally connected device.

The solid-state storage device controller 202 includes a master controller 224 that controls higher-level functions within the solid-state storage device 102. The master controller 224, in various embodiments, controls data flow by interpreting object requests and other requests, directs creation of indexes to map object identifiers associated with data to physical locations of associated data, coordinating DMA requests, etc. Many of the functions described herein are controlled wholly or in part by the master controller 224.

In one embodiment, the master controller 224 uses embedded controller(s). In another embodiment, the master controller 224 uses local memory such as a dynamic memory array 230 (dynamic random access memory “DRAM”), a static memory array 323 (static random access memory “SRAM”), etc. In one embodiment, the local memory is controlled using the master controller 224. In another embodiment, the master controller accesses the local memory via a memory controller 228. In another embodiment, the master controller runs a Linux server and may support various common server interfaces, such as the World Wide Web, hyper-text markup language (“HTML”), etc. In another embodiment, the master controller 224 uses a nano-processor. The master controller 224 may be constructed using programmable or standard logic, or any combination of controller types listed above. One skilled in the art will recognize many embodiments for the master controller.

In one embodiment, where the storage device 152/solid-state storage device controller 202 manages multiple data storage devices/solid-state storage 110 a-n, the master controller 224 divides the work load among internal controllers, such as the solid-state storage controllers 104 a-n. For example, the master controller 224 may divide an object to be written to the data storage devices (e.g. solid-state storage 110 a-n) so that a portion of the object is stored on each of the attached data storage devices. This feature is a performance enhancement allowing quicker storage and access to an object. In one embodiment, the master controller 224 is implemented using an FPGA. In another embodiment, the firmware within the master controller 224 may be updated through the management bus 236, the system bus 240 over a network connected to a NIC 244 or other device connected to the system bus 240.

In one embodiment, the master controller 224, which manages objects, emulates block storage such that a computer 102 or other device connected to the storage device 152/solid-state storage device 102 views the storage device 152/solid-state storage device 102 as a block storage device and sends data to specific physical addresses in the storage device 152/solid-state storage device 102. The master controller 224 then divides up the blocks and stores the data blocks as it would objects. The master controller 224 then maps the blocks and physical address sent with the block to the actual locations determined by the master controller 224. The mapping is stored in the object index. Typically, for block emulation, a block device application program interface (“API”) is provided in a driver in the computer 112, client 114, or other device wishing to use the storage device 152/solid-state storage device 102 as a block storage device.

In another embodiment, the master controller 224 coordinates with NIC controllers 244 and embedded RDMA controllers 246 to deliver just-in-time RDMA transfers of data and command sets. NIC controller 244 may be hidden behind a non-transparent port to enable the use of custom drivers. Also, a driver on a client 114 may have access to the computer network 118 through an I/O memory driver using a standard stack API and operating in conjunction with NICs 244.

In one embodiment, the master controller 224 is also a redundant array of independent drive (“RAID”) controller. Where the data storage device/solid-state storage device 102 is networked with one or more other data storage devices/solid-state storage devices 102, the master controller 224 may be a RAID controller for single tier RAID, multi-tier RAID, progressive RAID, etc. The master controller 224 also allows some objects to be stored in a RAID array and other objects to be stored without RAID. In another embodiment, the master controller 224 may be a distributed RAID controller element. In another embodiment, the master controller 224 may comprise many RAID, distributed RAID, and other functions as described elsewhere.

In one embodiment, the master controller 224 coordinates with single or redundant network managers (e.g. switches) to establish routing, to balance bandwidth utilization, failover, etc. In another embodiment, the master controller 224 coordinates with integrated application specific logic (via local bus 206) and associated driver software. In another embodiment, the master controller 224 coordinates with attached application specific processors 258 or logic (via the external system bus 240) and associated driver software. In another embodiment, the master controller 224 coordinates with remote application specific logic (via the computer network 118) and associated driver software. In another embodiment, the master controller 224 coordinates with the local bus 206 or external bus attached hard disk drive (“HDD”) storage controller.

In one embodiment, the master controller 224 communicates with one or more storage controllers 254 where the storage device/solid-state storage device 102 may appear as a storage device connected through a SCSI bus, Internet SCSI (“iSCSI”), fiber channel, etc. Meanwhile the storage device/solid-state storage device 102 may autonomously manage objects and may appear as an object file system or distributed object file system. The master controller 224 may also be accessed by peer controllers 256 and/or application specific processors 258.

In another embodiment, the master controller 224 coordinates with an autonomous integrated management controller to periodically validate FPGA code and/or controller software, validate FPGA code while running (reset) and/or validate controller software during power on (reset), support external reset requests, support reset requests due to watchdog timeouts, and support voltage, current, power, temperature, and other environmental measurements and setting of threshold interrupts. In another embodiment, the master controller 224 manages garbage collection to free erase blocks for reuse. In another embodiment, the master controller 224 manages wear leveling. In another embodiment, the master controller 224 allows the data storage device/solid-state storage device 102 to be partitioned into multiple virtual devices and allows partition-based media encryption. In yet another embodiment, the master controller 224 supports a solid-state storage controller 104 with advanced, multi-bit ECC correction. One of skill in the art will recognize other features and functions of a master controller 224 in a storage controller 152, or more specifically in a solid-state storage device 102.

In one embodiment, the solid-state storage device controller 202 includes a memory controller 228 which controls a dynamic random memory array 230 and/or a static random memory array 232. As stated above, the memory controller 228 may be independent or integrated with the master controller 224. The memory controller 228 typically controls volatile memory of some type, such as DRAM (dynamic random memory array 230) and SRAM (static random memory array 232). In other examples, the memory controller 228 also controls other memory types such as electrically erasable programmable read only memory (“EEPROM”), etc. In other embodiments, the memory controller 228 controls two or more memory types and the memory controller 228 may include more than one controller. Typically, the memory controller 228 controls as much SRAM 232 as is feasible and by DRAM 230 to supplement the SRAM 232.

In one embodiment, the object index is stored in memory 230, 232 and then periodically off-loaded to a channel of the solid-state storage 110 n or other non-volatile memory. One of skill in the art will recognize other uses and configurations of the memory controller 228, dynamic memory array 230, and static memory array 232.

In one embodiment, the solid-state storage device controller 202 includes a DMA controller 226 that controls DMA operations between the storage device/solid-state storage device 102 and one or more external memory controllers 250 and associated external memory arrays 252 and CPUs 248. Note that the external memory controllers 250 and external memory arrays 252 are called external because they are external to the storage device/solid-state storage device 102. In addition the DMA controller 226 may also control RDMA operations with requesting devices through a NIC 244 and associated RDMA controller 246. DMA and RDMA are explained in more detail below.

In one embodiment, the solid-state storage device controller 202 includes a management controller 234 connected to a management bus 236. Typically the management controller 234 manages environmental metrics and status of the storage device/solid-state storage device 102. The management controller 234 may monitor device temperature, fan speed, power supply settings, etc. over the management bus 236. The management controller may support the reading and programming of erasable programmable read only memory (“EEPROM”) for storage of FPGA code and controller software. Typically the management bus 236 is connected to the various components within the storage device/solid-state storage device 102. The management controller 234 may communicate alerts, interrupts, etc. over the local bus 206 or may include a separate connection to a system bus 240 or other bus. In one embodiment the management bus 236 is an Inter-Integrated Circuit (“I²C”) bus. One of skill in the art will recognize other related functions and uses of a management controller 234 connected to components of the storage device/solid-state storage device 102 by a management bus 236.

In one embodiment, the solid-state storage device controller 202 includes miscellaneous logic 242 that may be customized for a specific application. Typically where the solid-state device controller 202 or master controller 224 is/are configured using a FPGA or other configurable controller, custom logic may be included based on a particular application, customer requirement, storage requirement, etc.

Data Pipeline

FIG. 3 is a schematic block diagram illustrating one embodiment 300 of a solid-state storage controller 104 with a write data pipeline 106 and a read data pipeline 108 in a solid-state storage device 102 in accordance with the present invention. The embodiment 300 includes a data bus 204, a local bus 206, and buffer control 208, which are substantially similar to those described in relation to the solid-state storage device controller 202 of FIG. 2. The write data pipeline includes a packetizer 302 and an error-correcting code (“ECC”) generator 304. In other embodiments, the write data pipeline includes an input buffer 306, a write synchronization buffer 308, a write program module 310, a compression module 312, an encryption module 314, a garbage collector bypass 316 (with a portion within the read data pipeline), a media encryption module 318, and a write buffer 320. The read data pipeline 108 includes a read synchronization buffer 328, an ECC correction module 322, a depacketizer 324, an alignment module 326, and an output buffer 330. In other embodiments, the read data pipeline 108 may include a media decryption module 332, a portion of the garbage collector bypass 316, a decryption module 334, a decompression module 336, and a read program module 338. The solid-state storage controller 104 may also include control and status registers 340 and control queues 342, a bank interleave controller 344, a synchronization buffer 346, a storage bus controller 348, and a multiplexer (“MUX”) 350. The components of the solid-state controller 104 and associated write data pipeline 106 and read data pipeline 108 are described below. In other embodiments, synchronous solid-state storage 110 may be used and synchronization buffers 308 328 may be eliminated.

Write Data Pipeline

The write data pipeline 106 includes a packetizer 302 that receives a data or N metadata segment to be written to the solid-state storage, either directly or indirectly through another write data pipeline 106 stage, and creates one or more packets sized for the solid-state storage 110. The data or metadata segment is typically part of an object, but may also include an entire object. In another embodiment, the data segment is part of a block of data, but may also include an entire block of data. Typically, an object is received from a computer 112, client 114, or other computer or device and is transmitted to the solid-state storage device 102 in data segments streamed to the solid-state storage device 102 or computer 112. A data segment may also be known by another name, such as data parcel, but as referenced herein includes all or a portion of an object or data block.

Each object is stored as one or more packets. Each object may have one or more container packets. Each packet contains a header. The header may include a header type field. Type fields may include data, object attribute, metadata, data segment delimiters (multi-packet), object structures, object linkages, and the like. The header may also include information regarding the size of the packet, such as the number of bytes of data included in the packet. The length of the packet may be established by the packet type. The header may include information that establishes the relationship of the packet to the object. An example might be the use of an offset in a data packet header to identify the location of the data segment within the object. One of skill in the art will recognize other information that may be included in a header added to data by a packetizer 302 and other information that may be added to a data packet.

Each packet includes a header and possibly data from the data or metadata segment. The header of each packet includes pertinent information to relate the packet to the object to which the packet belongs. For example, the header may include an object identifier and offset that indicates the data segment, object, or data block from which the data packet was formed. The header may also include a logical address used by the storage bus controller 348 to store the packet. The header may also include information regarding the size of the packet, such as the number of bytes included in the packet. The header may also include a sequence number that identifies where the data segment belongs with respect to other packets within the object when reconstructing the data segment or object. The header may include a header type field. Type fields may include data, object attributes, metadata, data segment delimiters (multi-packet), object structures, object linkages, and the like. One of skill in the art will recognize other information that may be included in a header added to data or metadata by a packetizer 302 and other information that may be added to a packet.

The write data pipeline 106 includes an ECC generator 304 that generates one or more error-correcting codes (“ECC”) for the one or more packets received from the packetizer 302. The ECC generator 304 typically uses an error correcting algorithm to generate ECC which is stored with the packet. The ECC stored with the packet is typically used to detect and correct errors introduced into the data through transmission and storage. In one embodiment, packets are streamed into the ECC generator 304 as un-encoded blocks of length N. A syndrome of length S is calculated, appended and output as an encoded block of length N+S. The value of N and S are dependent upon the characteristics of the algorithm which is selected to achieve specific performance, efficiency, and robustness metrics. In the preferred embodiment, there is no fixed relationship between the ECC blocks and the packets; the packet may comprise more than one ECC block; the ECC block may comprise more than one packet; and a first packet may end anywhere within the ECC block and a second packet may begin after the end of the first packet within the same ECC block. In the preferred embodiment, ECC algorithms are not dynamically modified. In a preferred embodiment, the ECC stored with the data packets is robust enough to correct errors in more than two bits.

Beneficially, using a robust ECC algorithm allowing more than single bit correction or even double bit correction allows the life of the solid-state storage 110 to be extended. For example, if flash memory is used as the storage medium in the solid-state storage 110, the flash memory may be written approximately 100,000 times without error per erase cycle. This usage limit may be extended using a robust ECC algorithm. Having the ECC generator 304 and corresponding ECC correction module 322 onboard the solid-state storage device 102, the solid-state storage device 102 can internally correct errors and has a longer useful life than if a less robust ECC algorithm is used, such as single bit correction. However, in other embodiments the ECC generator 304 may use a less robust algorithm and may correct single-bit or double-bit errors. In another embodiment, the solid-state storage device 110 may comprise less reliable storage such as multi-level cell (“MLC”) flash in order to increase capacity, which storage may not be sufficiently reliable without more robust ECC algorithms.

In one embodiment, the write pipeline 106 includes an input buffer 306 that receives a data segment to be written to the solid-state storage 110 and stores the incoming data segments until the next stage of the write data pipeline 106, such as the packetizer 302 (or other stage for a more complex write data pipeline 106) is ready to process the next data segment. The input buffer 306 typically allows for discrepancies between the rate data segments are received and processed by the write data pipeline 106 using an appropriately sized data buffer. The input buffer 306 also allows the data bus 204 to transfer data to the write data pipeline 106 at rates greater than can be sustained by the write data pipeline 106 in order to improve efficiency of operation of the data bus 204. Typically when the write data pipeline 106 does not include an input buffer 306, a buffering function is performed elsewhere, such as in the solid-state storage device 102 but outside the write data pipeline 106, in the computer 112, such as within a network interface card (“NIC”), or at another device, for example when using remote direct memory access (“RDMA”).

In another embodiment, the write data pipeline 106 also includes a write synchronization buffer 308 that buffers packets received from the ECC generator 304 prior to writing the packets to the solid-state storage 110. The write synch buffer 308 is located at a boundary between a local clock domain and a solid-state storage clock domain and provides buffering to account for the clock domain differences. In other embodiments, synchronous solid-state storage 110 may be used and synchronization buffers 308 328 may be eliminated.

In one embodiment, the write data pipeline 106 also includes a media encryption module 318 that receives the one or more packets from the packetizer 302, either directly or indirectly, and encrypts the one or more packets using an encryption key unique to the solid-state storage device 102 prior to sending the packets to the ECC generator 304. Typically, the entire packet is encrypted, including the headers. In another embodiment, headers are not encrypted. In this document, encryption key is understood to mean a secret encryption key that is managed externally from an embodiment that integrates the solid-state storage 110 and where the embodiment requires encryption protection. The media encryption module 318 and corresponding media decryption module 332 provide a level of security for data stored in the solid-state storage 110. For example, where data is encrypted with the media encryption module 318, if the solid-state storage 110 is connected to a different solid-state storage controller 104, solid-state storage device 102, or computer 112, the contents of the solid-state storage 110 typically could not be read without use of the same encryption key used during the write of the data to the solid-state storage 110 without significant effort.

In a typical embodiment, the solid-state storage device 102 does not store the encryption key in non-volatile storage and allows no external access to the encryption key. The encryption key is provided to the solid-state storage controller 104 during initialization. The solid-sate storage device 102 may use and store a non-secret cryptographic nonce that is used in conjunction with an encryption key. A different nonce may be stored with every packet. Data segments may be split between multiple packets with unique nonces for the purpose of improving protection by the encryption algorithm. The encryption key may be received from a client 114, a computer 112, key manager, or other device that manages the encryption key to be used by the solid-state storage controller 104. In another embodiment, the solid-state storage 110 may have two or more partitions and the solid-state storage controller 104 behaves as though it were two or more solid-state storage controllers 104, each K operating on a single partition within the solid-state storage 110. In this embodiment, a unique media encryption key may be used with each partition.

In another embodiment, the write data pipeline 106 also includes an encryption module 314 that encrypts a data or metadata segment received from the input buffer 306, either directly or indirectly, prior sending the data segment to the packetizer 302, the data segment encrypted using an encryption key received in conjunction with the data segment. The encryption module 314 differs from the media encryption module 318 in that the encryption keys used by the encryption module 318 to encrypt data may not be common to all data stored within the solid-state storage device 102 but may vary on an object basis and received in conjunction with receiving data segments as described below. For example, an encryption key for a data segment to be encrypted by the encryption module 318 may be received with the data segment or may be received as part of a command to write an object to which the data segment belongs. The solid-sate storage device 102 may use and store a non-secret cryptographic nonce in each object packet that is used in conjunction with the encryption key. A different nonce may be stored with every packet. Data segments may be split between multiple packets with unique nonces for the purpose of improving protection by the encryption algorithm. In one embodiment, the nonce used by the media encryption module 318 is the same as that used by the encryption module 314.

The encryption key may be received from a client 114, a computer 112, key manager, or other device that holds the encryption key to be used to encrypt the data segment. In one embodiment, encryption keys are transferred to the solid-state storage controller 104 from one of a solid-state storage device 102, computer 112, client 114, or other external agent which has the ability to execute industry standard methods to securely transfer and protect private and public keys.

In one embodiment, the encryption module 318 encrypts a first packet with a first encryption key received in conjunction with the packet and encrypts a second packet with a second encryption key received in conjunction with the second packet. In another embodiment, the encryption module 318 encrypts a first packet with a first encryption key received in conjunction with the packet and passes a second data packet on to the next stage without encryption. Beneficially, the encryption module 318 included in the write data pipeline 106 of the solid-state storage device 102 allows object-by-object or segment-by-segment data encryption without a single file system or other external system to keep track of the different encryption keys used to store corresponding objects or data segments. Each requesting device 155 or related key manager independently manages encryption keys used to encrypt only the objects or data segments sent by the requesting device 155.

In another embodiment, the write data pipeline 106 includes a compression module 312 that compresses the data for metadata segment prior to sending the data segment to the packetizer 302. The compression module 312 typically compresses a data or metadata segment using a compression routine known to those of skill in the art to reduce the storage size of the segment. For example, if a data segment includes a string of 512 zeros, the compression module 312 may replace the 512 zeros with code or token indicating the 512 zeros where the code is much more compact than the space taken by the 512 zeros.

In one embodiment, the compression module 312 compresses a first segment with a first compression routine and passes along a second segment without compression. In another embodiment, the compression module 312 compresses a first segment with a first compression routine and compresses the second segment with a second compression routine. Having this flexibility within the solid-state storage device 102 is beneficial so that clients 114 or other devices writing data to the solid-state storage device 102 may each specify a compression routine or so that one can specify a compression routine while another specifies no compression. Selection of compression routines may also be selected according to default settings on a per object type or object class basis. For example, a first object of a specific object may be able to override default compression routine settings and a second object of the same object class and object type may use the default compression routine and a third object of the same object class and object type may use no compression.

In one embodiment, the write data pipeline 106 includes a garbage collector bypass 316 that receives data segments from the read data pipeline 108 as part of a data bypass in a garbage collection system. A garbage collection system typically marks packets that are no longer valid, typically because the packet is marked for deletion or has been modified and the modified data is stored in a different location. At some point, the garbage collection system determines that a particular section of storage may be recovered. This determination may be due to a lack of available storage capacity, the percentage of data marked as invalid reaching a threshold, a consolidation of valid data, an error detection rate for that section of storage reaching a threshold, or improving performance based on data distribution, etc. Numerous factors may be considered by a garbage collection algorithm to determine when a section of storage is to be recovered.

Once a section of storage has been marked for recovery, valid packets in the section typically must be relocated. The garbage collector bypass 316 allows packets to be read into the read data pipeline 108 and then transferred directly to the write data pipeline 106 without being routed out of the solid-state storage controller 104. In a preferred embodiment, the garbage collector bypass 316 is part of an autonomous garbage collector system that operates within the solid-state storage device 102. This allows the solid-state storage device 102 to manage data so that data is systematically spread throughout the solid-state storage 110 to improve performance, data reliability and to avoid overuse and underuse of any one location or area of the solid-state storage 110 and to lengthen the useful life of the solid-state storage 110.

The garbage collector bypass 316 coordinates insertion of segments into the write data pipeline 106 with other segments being written by clients 116 or other devices. In the depicted embodiment, the garbage collector bypass 316 is before the packetizer 302 in the write data pipeline 106 and after the depacketizer 324 in the read data pipeline 108, but may also be located elsewhere in the read and write data pipelines 106, 108. The garbage collector bypass 316 may be used during a flush of the write pipeline 106 to fill the remainder of the virtual page in order to improve the efficiency of storage within the Solid-State Storage 110 and thereby reduce the frequency of garbage collection.

In one embodiment, the write data pipeline 106 includes a write buffer 320 that buffers data for efficient write operations. Typically, the write buffer 320 includes enough capacity for packets to fill at least one virtual page in the solid-state storage 110. This allows a write operation to send an entire page of data to the solid-state storage 110 without interruption. By sizing the write buffer 320 of the write data pipeline 106 and buffers within the read data pipeline 108 to be the same capacity or larger than a storage write buffer within the solid-state storage 110, writing and reading data is more efficient since a single write command may be crafted to send a full virtual page of data to the solid-state storage 110 instead of multiple commands.

While the write buffer 320 is being filled, the solid-state storage 110 may be used for other read operations. This is advantageous because other solid-state devices with a smaller write buffer or no write buffer may tie up the solid-state storage when data is written to a storage write buffer and data flowing into the storage write buffer stalls. Read operations will be blocked until the entire storage write buffer is filled and programmed. Another approach for systems without a write buffer or a small write buffer is to flush the storage write buffer that is not full in order to enable reads. Again this is inefficient because multiple write/program cycles are required to fill a page.

For depicted embodiment with a write buffer 320 sized larger than a virtual page, a single write command, which includes numerous subcommands, can then be followed by a single program command to transfer the page of data from the storage write buffer in each solid-state storage element 216, 218, 220 to the designated page within each solid-state storage element 216, 218, 220. This technique has the benefits of eliminating partial page programming, which is known to reduce data reliability and durability and freeing up the destination bank for reads and other commands while the buffer fills.

In one embodiment, the write buffer 320 is a ping-pong buffer where one side of the buffer is filled and then designated for transfer at an appropriate time while the other side of the ping-pong buffer is being filled. In another embodiment, the write buffer 320 includes a first-in first-out (“FIFO”) register with a capacity of more than a virtual page of data segments. One of skill in the art will recognize other write buffer 320 configurations that allow a virtual page of data to be stored prior to writing the data to the solid-state storage 110.

In another embodiment, the write buffer 320 is sized smaller than a virtual page so that less than a page of information could be written to a storage write buffer in the solid-state storage 110. In the embodiment, to prevent a stall in the write data pipeline 106 from holding up read operations, data is queued using the garbage collection system that needs to be moved from one location to another as part of the garbage collection process. In case of a data stall in the write data pipeline 106, the data can be fed through the garbage collector bypass 316 to the write buffer 320 and then on to the storage write buffer in the solid-state storage 110 to fill the pages of a virtual page prior to programming the data. In this way a data stall in the write data pipeline 106 would not stall reading from the solid-state storage device 106.

In another embodiment, the write data pipeline 106 includes a write program module 310 with one or more user-definable functions within the write data pipeline 106. The write program module 310 allows a user to customize the write data pipeline 106. A user may customize the write data pipeline 106 based on a particular data requirement or application. Where the solid-state storage controller 104 is an FPGA, the user may program the write data pipeline 106 with custom commands and functions relatively easily. A user may also use the write program module 310 to include custom functions with an ASIC, however, customizing an ASIC may be more difficult than with an FPGA. The write program module 310 may include buffers and bypass mechanisms to allow a first data segment to execute in the write program module 310 while a second data segment may continue through the write data pipeline 106. In another embodiment, the write program module 310 may include a processor core that can be programmed through software.

Note that the write program module 310 is shown between the input buffer 306 and the compression module 312, however, the write program module 310 could be anywhere in the write data pipeline 106 and may be distributed among the various stages 302-320. In addition, there may be multiple write program modules 310 distributed among the various states 302-320 that are programmed and operate independently. In addition, the order of the stages 302-320 may be altered. One of skill in the art will recognize workable alterations to the order of the stages 302-320 based on particular user requirements.

Read Data Pipeline

The read data pipeline 108 includes an ECC correction module 322 that determines if a data error exists in ECC blocks a requested packet received from the solid-state storage 110 by using ECC stored with each ECC block of the requested packet. The ECC correction module 322 then corrects any errors in the requested packet if any error exists and the errors are correctable using the ECC. For example, if the ECC can detect an error in six bits but can only correct three bit errors, the ECC correction module 322 corrects ECC blocks of the requested packet with up to three bits in error. The ECC correction module 322 corrects the bits in error by changing the bits in error to the correct one or zero state so that the requested data packet is identical to when it was written to the solid-state storage 110 and the ECC was generated for the packet.

If the ECC correction module 322 determines that the requested packets contains more bits in error than the ECC can correct, the ECC correction module 322 cannot correct the errors in the corrupted ECC blocks of the requested packet and sends an interrupt. In one embodiment, the ECC correction module 322 sends an interrupt with a message indicating that the requested packet is in error. The message may include information that the ECC correction module 322 cannot correct the errors or the inability of the ECC correction module 322 to correct the errors may be implied. In another embodiment, the ECC correction module 322 sends the corrupted ECC blocks of the requested packet with the interrupt and/or the message.

In the preferred embodiment, a corrupted ECC block or portion of a corrupted ECC block of the requested packet that cannot be corrected by the ECC correction module 322 is read by the master controller 224, corrected, and returned to the ECC correction module 322 for further processing by the read data pipeline 108. In one embodiment, a corrupted ECC block or portion of a corrupted ECC block of the requested packet is sent to the device requesting the data. The requesting device 155 may correct the ECC block or replace the data using another copy, such as a backup or mirror copy, and then may use the replacement data of the requested data packet or return it to the read data pipeline 108. The requesting device 155 may use header information in the requested packet in error to identify data required to replace the corrupted requested packet or to replace the object to which the packet belongs. In another preferred embodiment, the solid-state storage controller 104 stores data using some type of RAID and is able to recover the corrupted data. In another embodiment, the ECC correction module 322 sends and interrupt and/or message and the receiving device fails the read operation associated with the requested data packet. One of skill in the art will recognize other options and actions to be taken as a result of the ECC correction module 322 determining that one or more ECC blocks of the requested packet are corrupted and that the ECC correction module 322 cannot correct the errors.

The read data pipeline 108 includes a depacketizer 324 that receives ECC blocks of the requested packet from the ECC correction module 322, directly or indirectly, and checks and removes one or more packet headers. The depacketizer 324 may validate the packet headers by checking packet identifiers, data length, data location, etc. within the headers. In one embodiment, the header includes a hash code that can be used to validate that the packet delivered to the read data pipeline 108 is the requested packet. The depacketizer 324 also removes the headers from the requested packet added by the packetizer 302. The depacketizer 324 may directed to not operate on certain packets but pass these forward without modification. An example might be a container label that is requested during the course of a rebuild process where the header information is required by the object index reconstruction module 272. Further examples include the transfer of packets of various types destined for use within the solid-state storage device 102. In another embodiment, the depacketizer 324 operation may be packet type dependent.

The read data pipeline 108 includes an alignment module 326 that receives data from the depacketizer 324 and removes unwanted data. In one embodiment, a read command sent to the solid-state storage 110 retrieves a packet of data. A device requesting the data may not require all data within the retrieved packet and the alignment module 326 removes the unwanted data. If all data within a retrieved page is requested data, the alignment module 326 does not remove any data.

The alignment module 326 re-formats the data as data segments of an object in a form compatible with a device requesting the data segment prior to forwarding the data segment to the next stage. Typically, as data is processed by the read data pipeline 108, the size of data segments or packets changes at various stages. The alignment module 326 uses received data to format the data into data segments suitable to be sent to the requesting device 155 and joined to form a response. For example, data from a portion of a first data packet may be combined with data from a portion of a second data packet. If a data segment is larger than a data requested by the requesting device, the alignment module 326 may discard the unwanted data.

In one embodiment, the read data pipeline 108 includes a read synchronization buffer 328 that buffers one or more requested packets read from the solid-state storage 110 prior to processing by the read data pipeline 108. The read synchronization buffer 328 is at the boundary between the solid-state storage clock domain and the local bus clock domain and provides buffering to account for the clock domain differences.

In another embodiment, the read data pipeline 108 includes an output buffer 330 that receives requested packets from the alignment module 326 and stores the packets prior to transmission to the requesting device. The output buffer 330 accounts for differences between when data segments are received from stages of the read data pipeline 108 and when the data segments are transmitted to other parts of the solid-state storage controller 104 or to the requesting device. The output buffer 330 also allows the data bus 204 to receive data from the read data pipeline 108 at rates greater than can be sustained by the read data pipeline 108 in order to improve efficiency of operation of the data bus 204.

In one embodiment, the read data pipeline 108 includes a media decryption module 332 that receives one or more encrypted requested packets from the ECC correction module 322 and decrypts the one or more requested packets using the encryption key unique to the solid-state storage device 102 prior to sending the one or more requested packets to the depacketizer 324. Typically the encryption key used to decrypt data by the media decryption module 332 is identical to the encryption key used by the media encryption module 318. In another embodiment, the solid-state storage 110 may have two or more partitions and the solid-state storage controller 104 behaves as though it were two or more solid-state storage controllers 104 each operating on a single partition within the solid-state storage 110. In this embodiment, a unique media encryption key may be used with each partition.

In another embodiment, the read data pipeline 108 includes a decryption module 334 that decrypts a data segment formatted by the depacketizer 324 prior to sending the data segment to the output buffer 330. The data segment decrypted using an encryption key received in conjunction with the read request that initiates retrieval of the requested packet received by the read synchronization buffer 328. The decryption module 334 may decrypt a first packet with an encryption key received in conjunction with the read request for the first packet and then may decrypt a second packet with a different encryption key or may pass the second packet on to the next stage of the read data pipeline 108 without decryption. Typically, the decryption module 334 uses a different encryption key to decrypt a data segment than the media decryption module 332 uses to decrypt requested packets. When the packet was stored with a non-secret cryptographic nonce, the nonce is used in conjunction with an encryption key to decrypt the data packet. The encryption key may be received from a client 114, a computer 112, key manager, or other device that manages the encryption key to be used by the solid-state storage controller 104.

In another embodiment, the read data pipeline 108 includes a decompression module 336 that decompresses a data segment formatted by the depacketizer 324. In the preferred embodiment, the decompression module 336 uses compression information stored in one or both of the packet header and the container label to select a complementary routine to that used to compress the data by the compression module 312. In another embodiment, the decompression routine used by the decompression module 336 is dictated by the device requesting the data segment being decompressed. In another embodiment, the decompression module 336 selects a decompression routine according to default settings on a per object type or object class basis. A first packet of a first object may be able to override a default decompression routine and a second packet of a second object of the same object class and object type may use the default decompression routine and a third packet of a third object of the same object class and object type may use no decompression.

In another embodiment, the read data pipeline 108 includes a read program module 338 that includes one or more user-definable functions within the read data pipeline 108. The read program module 338 has similar characteristics to the write program module 310 and allows a user to provide custom functions to the read data pipeline 108. The read program module 338 may be located as shown in FIG. 3, may be located in another position within the read data pipeline 108, or may include multiple parts in multiple locations within the read data pipeline 108. Additionally, there may be multiple read program modules 338 within multiple locations within the read data pipeline 108 that operate independently. One of skill in the art will recognize other forms of a read program module 338 within a read data pipeline 108. As with the write data pipeline 106, the stages of the read data pipeline 108 may be rearranged and one of skill in the art will recognize other orders of stages within the read data pipeline 108.

The solid-state storage controller 104 includes control and status registers 340 and corresponding control queues 342. The control and status registers 340 and control queues 342 facilitate control and sequencing commands and subcommands associated with data processed in the write and read data pipelines 106, 108. For example, a data segment in the packetizer 302 may have one or more corresponding control commands or instructions in a control queue 342 associated with the ECC generator. As the data segment is packetized, some of the instructions or commands may be executed within the packetizer 302. Other commands or instructions may be passed to the next control queue 342 through the control and status registers 340 as the newly formed data packet created from the data segment is passed to the next stage.

Commands or instructions may be simultaneously loaded into the control queues 342 for a packet being forwarded to the write data pipeline 106 with each pipeline stage pulling the appropriate command or instruction as the respective packet is executed by that stage. Similarly, commands or instructions may be simultaneously loaded into the control queues 342 for a packet being requested from the read data pipeline 108 with each pipeline stage pulling the appropriate command or instruction as the respective packet is executed by that stage. One of skill in the art will recognize other features and functions of control and status registers 340 and control queues 342.

The solid-state storage controller 104 and or solid-state storage device 102 may also include a bank interleave controller 344, a synchronization buffer 346, a storage bus controller 348, and a multiplexer (“MUX”) 350, which are described in relation to FIGS. 4A and 4B.

Bank Interleave

FIG. 4A is a schematic block diagram illustrating one embodiment 400 of a bank interleave controller 344 in the solid-state storage controller 104 in accordance with the present invention. The bank interleave controller 344 is connected to the control and status registers 340 and to the storage I/O bus 210 and storage control bus 212 through the MUX 350, storage bus controller 348, and synchronous buffer 346, which are described below. The bank interleave controller includes a read agent 402, a write agent 404, an erase agent 406, a management agent 408, read queues 410 a-n, write queues 412 a-n, erase queues 414 a-n, and management queues 416 a-n for the banks 214 in the solid-state storage 110, bank controllers 418 a-n, a bus arbiter 420, and a status MUX 422, which are described below. The storage bus controller 348 includes a mapping module 424 with a remapping module 430, a status capture module 426, and a NAND bus controller 428, which are described below.

The bank interleave controller 344 directs one or more commands to two or more queues in the bank interleave controller 344 and coordinates among the banks 214 of the solid-state storage 110 execution of the commands stored in the queues, such that a command of a first type executes on one bank 214 a while a command of a second type executes on a second bank 214 b. The one or more commands are separated by command type into the queues. Each bank 214 of the solid-state storage 110 has a corresponding set of queues within the bank interleave controller 344 and each set of queues includes a queue for each command type.

The bank interleave controller 344 coordinates among the banks 214 of the solid-state storage 110 execution of the commands stored in the queues. For example, a command of a first type executes on one bank 214 a while a command of a second type executes on a second bank 214 b. Typically the command types and queue types include read and write commands and queues 410, 412, but may also include other commands and queues that are storage media specific. For example, in the embodiment depicted in FIG. 4A, erase and management queues 414, 416 are included and would be appropriate for flash memory, NRAM, MRAM, DRAM, PRAM, etc.

For other types of solid-state storage 110, other types of commands and corresponding queues may be included without straying from the scope of the invention. The flexible nature of an FPGA solid-state storage controller 104 allows flexibility in storage media. If flash memory were changed to another solid-state storage type, the bank interleave controller 344, storage bus controller 348, and MUX 350 could be altered to accommodate the media type without significantly affecting the data pipelines 106, 108 and other solid-state storage controller 104 functions.

In the embodiment depicted in FIG. 4A, the bank interleave controller 344 includes, for each bank 214, a read queue 410 for reading data from the solid-state storage 110, a write queue 412 for write commands to the solid-state storage 110, an erase queue 414 for erasing an erase block in the solid-state storage, an a management queue 416 for management commands. The bank interleave controller 344 also includes corresponding read, write, erase, and management agents 402, 404, 406, 408. In another embodiment, the control and status registers 340 and control queues 342 or similar components queue commands for data sent to the banks 214 of the solid-state storage 110 without a bank interleave controller 344.

The agents 402, 404, 406, 408, in one embodiment, direct commands of the appropriate type destined for a particular bank 214 a to the correct queue for the bank 214 a. For example, the read agent 402 may receive a read command for bank-1 214 b and directs the read command to the bank-1 read queue 410 b. The write agent 404 may receive a write command to write data to a location in bank-0 214 a of the solid-state storage 110 and will then send the write command to the bank-0 write queue 412 a. Similarly, the erase agent 406 may receive an erase command to erase an erase block in bank-1 214 b and will then pass the erase command to the bank-1 erase queue 414 b. The management agent 408 typically receives management commands, status requests, and the like, such as a reset command or a request to read a configuration register of a bank 214, such as bank-0 214 a. The management agent 408 sends the management command to the bank-0 management queue 416 a.

The agents 402, 404, 406, 408 typically also monitor status of the queues 410, 412, 414, 416 and send status, interrupt, or other messages when the queues 410, 412, 414, 416 are full, nearly full, non-functional, etc. In one embodiment, the agents 402, 404, 406, 408 receive commands and generate corresponding sub-commands. In one embodiment, the agents 402, 404, 406, 408 receive commands through the control & status registers 340 and generate corresponding sub-commands which are forwarded to the queues 410, 412, 414, 416. One of skill in the art will recognize other functions of the agents 402, 404, 406, 408.

The queues 410, 412, 414, 416 typically receive commands and store the commands until required to be sent to the solid-state storage banks 214. In a typical embodiment, the queues 410, 412, 414, 416 are first-in, first-out (“FIFO”) registers or a similar component that operates as a FIFO. In another embodiment, the queues 410, 412, 414, 416 store commands in an order that matches data, order of importance, or other criteria.

The bank controllers 418 typically receive commands from the queues 410, 412, 414, 416 and generate appropriate subcommands. For example, the bank-0 write queue 412 a may receive a command to write a page of data packets to bank-0 214 a. The bank-0 controller 418 a may receive the write command at an appropriate time and may generate one or more write subcommands for each data packet stored in the write buffer 320 to be written to the page in bank-0 214 a. For example, bank-0 controller 418 a may generate commands to validate the status of bank 0 214 a and the solid-state storage array 216, select the appropriate location for writing one or more data packets, clear the input buffers within the solid-state storage memory array 216, transfer the one or more data packets to the input buffers, program the input buffers into the selected location, verify that the data was correctly programmed, and if program failures occur do one or more of interrupting the master controller, retrying the write to the same physical location, and retrying the write to a different physical location. Additionally, in conjunction with example write command, the storage bus controller 348 will cause the one or more commands to multiplied to each of the each of the storage I/O buses 210 a-n with the logical address of the command mapped to a first physical addresses for storage I/O bus 210 a, and mapped to a second physical address for storage I/O bus 210 b, and so forth as further described below.

Typically, bus arbiter 420 selects from among the bank controllers 418 and pulls subcommands from output queues within the bank controllers 418 and forwards these to the Storage Bus Controller 348 in a sequence that optimizes the performance of the banks 214. In another embodiment, the bus arbiter 420 may respond to a high level interrupt and modify the normal selection criteria. In another embodiment, the master controller 224 can control the bus arbiter 420 through the control and status registers 340. One of skill in the art will recognize other means by which the bus arbiter 420 may control and interleave the sequence of commands from the bank controllers 418 to the solid-state storage 110.

The bus arbiter 420 typically coordinates selection of appropriate commands, and corresponding data when required for the command type, from the bank controllers 418 and sends the commands and data to the storage bus controller 348. The bus arbiter 420 typically also sends commands to the storage control bus 212 to select the appropriate bank 214. For the case of flash memory or other solid-state storage 110 with an asynchronous, bi-directional serial storage I/O bus 210, only one command (control information) or set of data can be transmitted at a time. For example, when write commands or data are being transmitted to the solid-state storage 110 on the storage I/O bus 210, read commands, data being read, erase commands, management commands, or other status commands cannot be transmitted on the storage I/O bus 210. For example, when data is being read from the storage I/O bus 210, data cannot be written to the solid-state storage 110.

For example, during a write operation on bank-0 the bus arbiter 420 selects the bank-0 controller 418 a which may have a write command or a series of write sub-commands on the top of its queue which cause the storage bus controller 348 to execute the following sequence. The bus arbiter 420 forwards the write command to the storage bus controller 348, which sets up a write command by selecting bank-0 214 a through the storage control bus 212, sending a command to clear the input buffers of the solid-state storage elements 110 associated with the bank-0 214 a, and sending a command to validate the status of the solid-state storage elements 216, 218, 220 associated with the bank-0 214 a. The storage bus controller 348 then transmits a write subcommand on the storage I/O bus 210, which contains the physical addresses including the address of the logical erase block for each individual physical erase solid-stage storage element 216 a-m as mapped from the logical erase block address. The storage bus controller 348 then muxes the write buffer 320 through the write sync buffer 308 to the storage I/O bus 210 through the MUX 350 and streams write data to the appropriate page. When the page is full, then storage bus controller 348 causes the solid-state storage elements 216 a-m associated with the bank-0 214 a to program the input buffer to the memory cells within the solid-state storage elements 216 a-m. Finally, the storage bus controller 348 validates the status to ensure that page was correctly programmed.

A read operation is similar to the write example above. During a read operation, typically the bus arbiter 420, or other component of the bank interleave controller 344, receives data and corresponding status information and sends the data to the read data pipeline 108 while sending the status information on to the control and status registers 340. Typically, a read data command forwarded from bus arbiter 420 to the storage bus controller 348 will cause the MUX 350 to gate the read data on storage I/O bus 210 to the read data pipeline 108 and send status information to the appropriate control and status registers 340 through the status MUX 422.

The bus arbiter 420 coordinates the various command types and data access modes so that only an appropriate command type or corresponding data is on the bus at any given time. If the bus arbiter 420 has selected a write command, and write subcommands and corresponding data are being written to the solid-state storage 110, the bus arbiter 420 will not allow other command types on the storage I/O bus 210. Beneficially, the bus arbiter 420 uses timing information, such as predicted command execution times, along with status information received concerning bank 214 status to coordinate execution of the various commands on the bus with the goal of minimizing or eliminating idle time of the busses.

The master controller 224 through the bus arbiter 420 typically uses expected completion times of the commands stored in the queues 410, 412, 414, 416, along with status information, so that when the subcommands associated with a command are executing on one bank 214 a, other subcommands of other commands are executing on other banks 214 b-n. When one command is fully executed on a bank 214 a, the bus arbiter 420 directs another command to the bank 214 a. The bus arbiter 420 may also coordinate commands stored in the queues 410, 412, 414, 416 with other commands that are not stored in the queues 410, 412, 414, 416.

For example, an erase command may be sent out to erase a group of erase blocks within the solid-state storage 110. An erase command may take 10 to 1000 times more time to execute than a write or a read command or 10 to 100 times more time to execute than a program command. For N banks 214, the bank interleave controller 344 may split the erase command into N commands, each to erase a virtual erase block of a bank 214 a. While bank-0 214 a is executing an erase command, the bus arbiter 420 may select other commands for execution on the other banks 214 b-n. The bus arbiter 420 may also work with other components, such as the storage bus controller 348, the master controller 224, etc., to coordinate command execution among the buses. Coordinating execution of commands using the bus arbiter 420, bank controllers 418, queues 410, 412, 414, 416, and agents 402, 404, 406, 408 of the bank interleave controller 344 can dramatically increase performance over other solid-state storage systems without a bank interleave function.

In one embodiment, the solid-state controller 104 includes one bank interleave controller 344 that serves all of the storage elements 216, 218, 220 of the solid-state storage 110. In another embodiment, the solid-state controller 104 includes a bank interleave controller 344 for each row of storage elements 216 a-m, 218 a-m, 220 a-m. For example, one bank interleave controller 344 serves one row of storage elements SSS 0.0-SSS 0.N 216 a, 218 a, 220 a, a second bank interleave controller 344 serves a second row of storage elements SSS 1.0-SSS 1.N 216 b, 218 b, 220 b, etc.

FIG. 4B is a schematic block diagram illustrating an alternate embodiment 401 of a bank interleave controller in the solid-state storage controller in accordance with the present invention. The components 210, 212, 340, 346, 348, 350, 402-430 depicted in the embodiment shown in FIG. 4B are substantially similar to the bank interleave apparatus 400 described in relation to FIG. 4A except that each bank 214 includes a single queue 432 a-n and the read commands, write commands, erase commands, management commands, etc. for a bank (e.g. Bank-0 214 a) are directed to a single queue 432 a for the bank 214 a. The queues 432, in one embodiment, are FIFO. In another embodiment, the queues 432 can have commands pulled from the queues 432 in an order other than the order they were stored. In another alternate embodiment (not shown), the read agent 402, write agent 404, erase agent 406, and management agent 408 may be combined into a single agent assigning commands to the appropriate queues 432 a-n.

In another alternate embodiment (not shown), commands are stored in a single queue where the commands may be pulled from the queue in an order other than how they are stored so that the bank interleave controller 344 can execute a command on one bank 214 a while other commands are executing on the remaining banks 214 b-n. One of skill in the art will easily recognize other queue configurations and types to enable execution of a command on one bank 214 a while other commands are executing on other banks 214 b-n.

Storage-Specific Components

The solid-state storage controller 104 includes a synchronization buffer 346 that buffers commands and status messages sent and received from the solid-state storage 110. The synchronization buffer 346 is located at the boundary between the solid-state storage clock domain and the local bus clock domain and provides buffering to account for the clock domain differences. The synchronization buffer 346, write synchronization buffer 308, and read synchronization buffer 328 may be independent or may act together to buffer data, commands, status messages, etc. In the preferred embodiment, the synchronization K buffer 346 is located where there are the fewest number of signals crossing the clock domains. One skilled in the art will recognize that synchronization between clock domains may be arbitrarily moved to other locations within the solid-state storage device 102 in order to optimize some aspect of design implementation.

The solid-state storage controller 104 includes a storage bus controller 348 that interprets and translates commands for data sent to and read from the solid-state storage 110 and status messages received from the solid-state storage 110 based on the type of solid-state storage 110. For example, the storage bus controller 348 may have different timing requirements for different types of storage, storage with different performance characteristics, storage from different manufacturers, etc. The storage bus controller 348 also sends control commands to the storage control bus 212.

In the preferred embodiment, the solid-state storage controller 104 includes a MUX 350 that comprises an array of multiplexers 350 a-n where each multiplexer is dedicated to a row in the solid-state storage array 110. For example, multiplexer 350 a is associated with solid-state storage elements 216 a, 218 a, 220 a. MUX 350 routes the data from the write data pipeline 106 and commands from the storage bus controller 348 to the solid-state storage 110 via the storage I/O bus 210 and routes data and status messages from the solid-state storage 110 via the storage I/O bus 210 to the read data pipeline 106 and the control and status registers 340 through the storage bus controller 348, synchronization buffer 346, and bank interleave controller 344.

In the preferred embodiment, the solid-state storage controller 104 includes a MUX 350 for each row of solid-state storage elements (e.g. SSS 0.1 216 a, SSS 0.2 218 a, SSS 0.N 220 a). A MUX 350 combines data from the write data pipeline 106 and commands sent to the solid-state storage 110 via the storage I/O bus 210 and separates data to be processed by the read data pipeline 108 from commands. Packets stored in the write buffer 320 are directed on busses out of the write buffer 320 through a write synchronization buffer 308 for each row of solid-state storage elements (SSS x.0 to SSS x.N 216, 218, 220) to the MUX 350 for each row of solid-state storage elements (SSS x.0 to SSS x.N 216, 218, 220). The commands and read data are received by the MUXes 350 from the storage I/O bus 210. The MUXes 350 also direct status messages to the storage bus controller 348.

The storage bus controller 348 includes a mapping module 424. The mapping module 424 maps a logical address of an erase block to one or more physical addresses of an erase block. For example, a solid-state storage 110 with an array of twenty storage elements (e.g. SSS 0.0 to SSS M.0 216) per block 214 a may have a logical address for a particular erase block mapped to twenty physical addresses of the erase block, one physical address per storage element. Because the storage elements are accessed in parallel, erase blocks at the same position in each storage element in a row of storage elements 216 a, 218 a, 220 a will share a physical address. To select one erase block (e.g. in storage element SSS 0.0 216 a) instead of all erase blocks in the row (e.g. in storage elements SSS 0.0, 0.1, . . . 0.N 216 a, 218 a, 220 a), one bank (in this case bank-0 214 a) is selected.

This logical-to-physical mapping for erase blocks is beneficial because if one erase block becomes damaged or inaccessible, the mapping can be changed to map to another erase block. This mitigates the loss of losing an entire virtual erase block when one element's erase block is faulty. The remapping module 430 changes a mapping of a logical address of an erase block to one or more physical addresses of a virtual erase block (spread over the array of storage elements). For example, virtual erase block 1 may be mapped to erase block 1 of storage element SSS 0.0 216 a, to erase block 1 of storage element SSS1.0 216 b, . . . , and to storage element M.0 216 m, virtual erase block 2 may be mapped to erase block 2 of storage element SSS 0.1 218 a, to erase block 2 of storage element SSS1.1 218 b, . . . , and to storage element M.1 218 m, etc.

If erase block 1 of a storage element SSS0.0 216 a is damaged, experiencing errors due to wear, etc., or cannot be used for some reason, the remapping module could change the logical-to-physical mapping for the logical address that pointed to erase block 1 of virtual erase block 1. If a spare erase block (call it erase block 221) of storage element SSS 0.0 216 a is available and currently not mapped, the remapping module could change the mapping of virtual erase block 1 to point to erase block 221 of storage element SSS 0.0 216 a, while continuing to point to erase block 1 of storage element SSS1.0 216 b, erase block 1 of storage element SSS 2.0 (not shown) . . . , and to storage element M.0 216 m. The mapping module 424 or remapping module 430 could map erase blocks in a prescribed order (virtual erase block 1 to erase block 1 of the storage elements, virtual erase block 2 to erase block 2 of the storage elements, etc.) or may map erase blocks of the storage elements 216, 218, 220 in another order based on some other criteria.

In one embodiment, the erase blocks could be grouped by access time. Grouping by access time, meaning time to execute a command, such as programming (writing) data into pages of specific erase blocks, can level command completion so that a command executed across the erase blocks of a virtual erase block is not limited by the slowest erase block. In other embodiments, the erase blocks may be grouped by wear level, health, etc. One of skill in the art will recognize other factors to consider when mapping or remapping erase blocks.

In one embodiment, the storage bus controller 348 includes a status capture module 426 that receives status messages from the solid-state storage 110 and sends the status messages to the status MUX 422. In another embodiment, when the solid-state storage 110 is flash memory, the storage bus controller 348 includes a NAND bus controller 428. The NAND bus controller 428 directs commands from the read and write data pipelines 106, 108 to the correct location in the solid-state storage 110, coordinates timing of command execution based on characteristics of the flash memory, etc. If the solid-state storage 110 is another solid-state storage type, the NAND bus controller 428 would be replaced by a bus controller specific to the storage type. One of skill in the art will recognize other functions of a NAND bus controller 428.

Flow Charts

FIG. 5A is a schematic flow chart diagram illustrating one embodiment of a method 500 for managing data in a solid-state storage device 102 using a data pipeline in accordance with the present invention. The method 500 begins 502 and the input buffer 306 receives 504 one or more data segments to be written to the solid-state storage 110. The one or more data segments typically include at least a portion of an object but may be an entire object. The packetizer 302 may create one or more object specific packets in conjunction with an object. The packetizer 302 adds a header to each packet which typically includes the length of the packet and a sequence number for the packet within the object. The packetizer 302 receives 504 the one or more data or metadata segments that were stored in the input buffer 306 and packetizes 506 the one or more data or metadata segments by creating one or more packets sized for the solid-state storage 110 where each packet includes one header and data from the one or more segments.

Typically, a first packet includes an object identifier that identifies the object for which the packet was created. A second packet may include a header with information used by the solid-state storage device 102 to associate the second packet to the object identified in the first packet and offset information locating the second packet within the object, and data. The solid-state storage device controller 202 manages the bank 214 and physical area to which the packets are streamed.

The ECC generator 304 receives a packet from the packetizer 302 and generates 508 ECC for the data packets. Typically, there is no fixed relationship between packets and ECC blocks. An ECC block may comprise one or more packets. A packet may comprise one or more ECC blocks. A packet may start and end anywhere within an ECC block. A packet may start anywhere in a first ECC block and end anywhere in a subsequent ECC block.

The write synchronization buffer 308 buffers 510 the packets as distributed within the corresponding ECC blocks prior to writing ECC blocks to the solid-state storage 110 and then the solid-state storage controller 104 writes 512 the data at an appropriate time considering clock domain differences, and the method 500 ends 514. The write synch buffer 308 is located at the boundary between a local clock domain and a solid-state storage 110 clock domain. Note that the method 500 describes receiving one or more data segments and writing one or more data packets for convenience, but typically a stream of data segments is received and a group. Typically a number of ECC blocks comprising a complete virtual page of solid-state storage 110 are written to the solid-state storage 110. Typically the packetizer 302 receives data segments of one size and generates packets of another size. This necessarily requires data or metadata segments or parts of data or metadata segments to be combined to form data packets to capture all of the data of the segments into packets.

FIG. 5B is a schematic flow chart diagram illustrating one embodiment of a method for in-server SAN in accordance with the present invention. The method 500 begins 552 and the storage communication module 162 facilitates 554 communication between a first storage controller 152 a and at least one device external to the first server 112 a. The communication between the first storage controller 152 a and the external device is independent from the first server 112 a. The first storage controller 112 a is within the first server 112 a and the first storage controller 152 a controls at least one storage device 154 a. The first server 112 a includes a network interface 156 a collocated with the first server 112 a and the first storage controller 152 a. The in-server SAN module 164 services 556 a storage request and the method 501 ends 558. The in-server SAN module services 556 the storage request using a network protocol and/or a bus protocol. The in-server SAN module 164 services 556 the storage request independent from the first server 112 a and the service request is received from a client 114, 114 a.

FIG. 6 is a schematic flow chart diagram illustrating another embodiment of a method 600 for managing data in a solid-state storage device 102 using a data pipeline in accordance with the present invention. The method 600 begins 602 and the input buffer 306 receives 604 one or more data or metadata segments to be written to the solid-state storage 110. The packetizer 302 adds a header to each packet which typically includes the length of the packet within the object. The packetizer 302 receives 604 the one or more segments that were stored in the input buffer 306 and packetizes 606 the one or more segments by creating one or more packets sized for the solid-state storage 110 where each packet includes a header and data from the one or more segments.

The ECC generator 304 receives a packet from the packetizer 302 and generates 608 one or more ECC blocks for the packets. The write synchronization buffer 308 buffers 610 the packets as distributed within the corresponding ECC blocks prior to writing ECC blocks to the solid-state storage 110 and then the solid-state storage controller 104 writes 612 the data at an appropriate time considering clock domain differences. When data is requested from the solid-state storage 110, ECC blocks comprising one or more data packets are read into the read synchronization buffer 328 and buffered 614. The ECC blocks of the packet are received over the storage I/O bus 210. Since the storage I/O bus 210 is bi-directional, when data is read, write operations, command operations, etc. are halted.

The ECC correction module 322 receives the ECC blocks of the requested packets held in the read synchronization buffer 328 and corrects 616 errors within each ECC block as necessary. If the ECC correction module 322 determines that one or more errors exist in an ECC block and the errors are correctable using the ECC syndrom, the ECC correction module 322 corrects 616 the error in the ECC block. If the ECC correction module 322 determines that a detected error is not correctable using the ECC, the ECC correction module 322 sends an interrupt.

The depacketizer 324 receives 618 the requested packet after the ECC correction module 322 corrects any errors and depacketizes 618 the packets by checking and removing the packet header of each packet. The alignment module 326 receives packets after depacketizing, removes unwanted data, and re-formats 620 the data packets as data or metadata segments of an object in a form compatible with the device requesting the segment or object. The output buffer 330 receives requested packets after depacketizing and buffers the packets prior to transmission to the requesting device, and the method 600 ends 624.

FIG. 7 is a schematic flow chart diagram illustrating an embodiment of a method 700 for managing data in a solid-state storage device 102 using a bank interleave in accordance with the present invention. The method 600 begins 602 and the bank interleave controller 344 directs 604 one or more commands to two or more queues 410, 412, 414, 416. Typically the agents 402, 404, 406, 408 direct 604 the commands to the queues 410, 412, 414, 416 by command type. Each set of queues 410, 412, 414, 416 includes a queue for each command type. The bank interleave controller 344 coordinates 606 among the banks 214 execution of the commands stored in the queues 410, 412, 414, 416 so that a command of a first type executes on one bank 214 a while a command of a second type executes on a second bank 214 b, and the method 600 ends 608.

Storage Space Recovery

FIG. 8 is a schematic block diagram illustrating one embodiment of an apparatus 800 for garbage collection in a solid-state storage device 102 in accordance with the present invention. The apparatus 800 includes a sequential storage module 802, a storage division selection module 804, a data recovery module 806, and a storage division recovery module 808, which are described below. In other embodiments, the apparatus 800 includes a garbage marking module 810 and an erase module 812.

The apparatus 800 includes a sequential storage module 802 that sequentially writes data packets in a page within a storage division. The packets are sequentially stored whether they are new packets or modified packets. Modified packets are in this embodiment are typically not written back to a location where they were previously stored. In one embodiment, the sequential storage module 802 writes a packet to a first location in a page of a storage division, then to the next location in the page, and to the next, and the next, until the page is filled. The sequential storage module 802 then starts to fill the next page in the storage division. This continues until the storage division is filled.

In a preferred embodiment, the sequential storage module 802 starts writing packets to storage write buffers in the storage elements (e.g. SSS 0.0 to SSS M.0 216) of a bank (bank-0 214 a). When the storage write buffers are full, the solid-state storage controller 104 causes the data in the storage write buffers to be programmed into designated pages within the storage elements 216 of the bank 214 a. Then another bank (e.g. bank-1 214 b) is selected and the sequential storage module 802 starts writing packets to storage write buffers of the storage elements 218 of the bank 214 b while the first bank-0 is programming the designated pages. When the storage write buffers of this bank 214 b are full, the contents of the storage write buffers are programmed into another designated page in each storage element 218. This process is efficient because while one bank 214 a is programming a page, storage write buffers of another bank 214 b can be filling.

The storage division includes a portion of a solid-state storage 110 in a solid-state storage device 102. Typically the storage division is an erase block. For flash memory, an erase operation on an erase block writes ones to every bit in the erase block by charging each cell. This is a lengthy process compared to a program operation which starts with a location being all ones, and as data is written, some bits are changed to zero by discharging the cells written with a zero. However, where the solid-state storage 110 is not flash memory or has flash memory where an erase cycle takes a similar amount of time as other operations, such as a read or a program, the storage division may not be required to be erased.

As used herein, a storage division is equivalent in area to an erase block but may or may not be erased. Where erase block is used herein, an erase block may refer to a particular area of a designated size within a storage element (e.g. SSS 0.0 216 a) and typically includes a certain quantity of pages. Where “erase block” is used in conjunction with flash memory, it is typically a storage division that is erased prior to being written. Where “erase block” is used with “solid-state storage,” it may or may not be erased. As used herein, an erase block may include one erase block or a group of erase blocks with one erase block in each of a row of storage elements (e.g. SSS 0.0 to SSS M.0 216 a-n), which may also be referred to herein as a virtual erase block. When referring to the logical construct associated with the virtual erase block, the erase blocks may be referred to herein as a logical erase block (“LEB”).

Typically, the packets are sequentially stored by order of processing. In one embodiment, where a write data pipeline 106 is used, the sequential storage module 802 stores packets in the order that they come out of the write data pipeline 106. This order may be a result of data segments arriving from a requesting device 155 mixed with packets of valid data that are being read from another storage division as valid data is being recovered from a storage division during a recovery operation as explained below. Re-routing recovered, valid data packets to the write data pipeline 106 may include the garbage collector bypass 316 as described above in relation to the solid-state storage controller 104 of FIG. 3.

The apparatus 800 includes a storage division selection module 804 that selects a storage division for recovery. Selecting a storage division for recovery may be to reuse the storage division by the sequential storage module 802 for writing data, thus adding the recovered storage division to the storage pool, or to recover valid data from the storage division after determining that the storage division is failing, unreliable, should be refreshed, or other reason to take the storage division temporarily or permanently out of the storage pool. In another embodiment, the storage division selection module 804 selects a storage division for recovery by identifying a storage division or erase block with a high amount of invalid data.

In another embodiment, the storage division selection module 804 selects a storage division for recovery by identifying a storage division or erase block with a low amount of wear. For example, identifying a storage division or erase block with a low amount of wear may include identifying a storage division with a low amount of invalid data, a low number of erase cycles, low bit error rate, or low program count (low number of times a page of data in a buffer is written to a page in the storage division; program count may be measured from when the device was manufactured, from when the storage division was last erased, from other arbitrary events, and from combinations of these). The storage division selection module 804 may also use any combination of the above or other parameters to determine a storage division with a low amount of wear. Selecting a storage division for recovery by determining a storage division with a low amount of wear may be desirable to find storage divisions that are under used, may be recovered for wear leveling, etc.

In another embodiment, the storage division selection module 804 selects a storage division for recovery by identifying a storage division or erase block with a high amount of wear. For example, identifying a storage division or erase block with a high amount of wear may include identifying a storage division with a high number of erase cycles, high bit error rate, a storage division with a non-recoverable ECC block, or high program count. The storage division selection module 804 may also use any combination of the above or other parameters to determine a storage division with a high amount of wear. Selecting a storage division for recovery by determining a storage division with a high amount of wear may be desirable to find storage divisions that are over used, may be recovered by refreshing the storage division using an erase cycle, etc. or to retire the storage division from service as being unusable.

The apparatus 800 includes a data recovery module 806 that reads valid data packets from the storage division selected for recovery, queues the valid data packets with other data packets to be written sequentially by the sequential storage module 802, and updates an index with a new physical address of the valid data written by the sequential storage module 802. Typically, the index is the object index mapping data object identifiers of objects to physical addresses of where packets derived from the data object are stored in the solid-state storage 110.

In one embodiment the apparatus 800 includes a storage division recovery module 808 that prepares the storage division for use or reuse and marks the storage division as available to the sequential storage module 802 for sequentially writing data packets after the data recovery module 806 has completed copying valid data from the storage division. In another embodiment, the apparatus 800 includes a storage division recovery module 808 that marks the storage division selected for recovery as unavailable for storing data. Typically this is due to the storage division selection module 804 identifying a storage division or erase block with a high amount of wear such that the storage division or erase block is not in condition to be used for reliable data storage.

In one embodiment, the apparatus 800 is in a solid-state storage device controller 202 of a solid-state storage device 102. In another embodiment, the apparatus 800 controls a solid-state storage device controller 202. In another embodiment, a portion of the apparatus 800 is in a solid-state storage device controller 202. In another embodiment, the object index updated by the data recovery module 806 is also located in the solid-state storage device controller 202

In one embodiment, the storage division is an erase block and the apparatus 800 includes an erase module 810 that erases an erase block selected for recovery after the data recovery module 806 has copied valid data packets from the selected erase block and before the storage division recovery module 808 marks the erase block as available. For flash memory and other solid-state storage with an erase operation taking much longer than read or write operations, erasing a data block prior to making it available for writing new data is desirable for efficient operation. Where the solid-state storage 110 is arranged in banks 214, the erase operation by the erase module 810 may be executed on one bank while other banks are executing reads, writes, or other operations.

In one embodiment, the apparatus 800 includes a garbage marking module 812 that identifies a data packet in a storage division as invalid in response to an operation indicating that the data packet is no longer valid. For example, if a data packet is deleted, the garbage marking module 812 may identify the data packet as invalid. A read-modify-write operation is another way for a data packet to be identified as invalid. In one embodiment, the garbage marking module 812 may identify the data packet as invalid by updating an index. In another embodiment, the garbage marking module 812 may identify the data packet as invalid by storing another data packet that indicates that the invalid data packet has been deleted. This is advantageous because storing, in the solid-state storage 110, information that the data packet has been deleted allows the object index reconstruction module 262 or similar module to reconstruct the object index with an entry indicating that the invalid data packet has been deleted.

In one embodiment, the apparatus 800 may be utilized to fill the remainder of a virtual page of data following a flush command in order to improve overall performance, where the flush command halts data flowing into the write pipeline 106 until the write pipeline 106 empties and all packets have been permanently written into non-volatile solid-state storage 110. This has the benefit of reducing the amount of garbage collection required, the amount of time used to erase storage divisions, and the amount of time required to program virtual pages. For example, a flush command may be received when only one small packet is prepared for writing into the virtual page of the solid-state storage 100. Programming this nearly empty virtual page might result in a need to immediately recover the wasted space, causing the valid data within the storage division to be unnecessarily garbage collected and the storage division erased, recovered and returned to the pool of available space for writing by the sequential storage module 802.

Marking the data packet as invalid rather than actually erasing an invalid data packet is efficient because, as mentioned above, for flash memory and other similar storage an erase operation takes a significant amount of time. Allowing a garbage collection system, as described in the apparatus 800, to operate autonomously within the solid-state storage 110 provides a way to separate erase operations from reads, writes, and other faster operations so that the solid-state storage device 102 can operate much faster than many other solid-state storage systems or data storage devices.

FIG. 9 is a schematic flow chart diagram illustrating an embodiment of a method 900 for storage recovery in accordance with the present invention. The method 900 begins 902 and the sequential storage module 802 sequentially writes 904 data packets in a storage division. The storage division is a portion of a solid-state storage 110 in a solid-state storage device 102. Typically a storage division is an erase block. The data packets are derived from an object and the data packets are sequentially stored by order of processing.

The storage division selection module 804 selects 906 a storage division for recovery and the data recovery module 806 reads 908 valid data packets from the storage division selected for recovery. Typically valid data packets are data packets that have not been marked for erasure or deletion or some other invalid data marking and are considered valid or “good” data. The data recovery module 806 queues 910 the valid data packets with other data packets scheduled to be written sequentially by the sequential storage module 802. The data recovery module 806 updates 912 an index with a new physical address of the valid data written by the sequential storage module 802. The index includes a mapping of physical addresses of data packets to object identifiers. The data packets are those stored in stored in the solid-state storage 110 and the object identifiers correspond to the data packets.

After the data recovery module 806 completes copying valid data from the storage division, the storage division recovery module 808 marks 914 the storage division selected for recovery as available to the sequential storage module 802 for sequentially writing data packets and the method 900 ends 916.

Device Shared Between Multiple Independent Hosts

FIG. 10 is a schematic block diagram illustrating one embodiment of a system 2500 for a device shared between multiple hosts in accordance with the present invention. The system includes a command proxy host 2502, one or more other hosts 2504, and a shared device 2506 connected through a system bus 2508, which are described below. The system also includes a computer network 116, a server 112, a client 114, and a storage device 150, which are substantially similar to those described above.

The command proxy host 2502 and other hosts 2504 typically each include a separate image of an operating system so each host 2502, 2504 executes an operating system independent of the other hosts 2502, 2504. In one embodiment, one or more hosts may include independent virtual machines with one or more operating systems operating above the virtual machine layer. A host 2502, 2504 includes one or more processors and may be included in a server 112, computer, or other device capable of running an operating system. In one embodiment, one or more hosts 2502, 2504 are in one computer, such as a mainframe computer. In another embodiment, at least one host 2502, 2504 is physically separated from the other hosts 2502, 2504.

In one embodiment, the command proxy host 2502 contains the root port. In another embodiment, the command proxy host 2502 executes in one of the two or more hosts 2504. In another embodiment, the command proxy host 2502 executes in a third party element managing commands to the shared device 2506 independent of the hosts 2504. In yet another embodiment, the command proxy host 2502 executes in a device that combines the root port, one of the hosts 2602, the shared device 2506, and the third party element managing commands. Root and root port are used herein interchangeably and include a root port and the associated process, processor, etc. One of skill in the art will recognize other forms of two or more hosts 2502, 2504 connected to a shared device 2506 by a system bus 2508.

For a particular shared device 2506, one of the hosts 2502, 2504 is designated as a command proxy host 2502 capable of communicating both with the other hosts 2504 and the shared device 2506. Typically, the command proxy host 2502 is capable of servicing interrupts from the shared device 2506. An interrupt may take on many forms known to those of skill in the art. In one embodiment, an interrupt may include information that the shared device 2506 has data to be transferred to a host 2504 or has already transferred data to the host 2504. The command proxy host 2052 is able to communicate with the hosts 2504 and the shared device 2506. The communications may be control requests and/or data transfers. One of skill in the art will recognize other characteristics and functions common to a designated command proxy host 2502.

The system 2500 includes at least one shared device 2506 connected to the system bus 2508. The shared device 2506 may be a storage device 150, a network interface 156, a graphic display driver, input/output (“I/O”) adapter, or other device capable of connecting to a system bus 2508 and capable of being shared between hosts 2502, 2504. Other devices may also be connected to the system bus 2506 in addition to the shared device 2506.

In one embodiment, the shared device 2506 is a network interface 156 that is connected to a computer network 116 to other devices, such as a client 114, server 112, storage device 150, etc. The shared device 2506, as a network interface 156, typically transfers data and control requests between a host 2502, 2504 and another device, such as a client 114, server 112, or storage device 150, and typically acts as a bridge between a network protocol running on the computer network 116 and the system bus 2508. One of skill in the art will recognize other suitable shared devices 2506 and configurations.

The system 2500 includes a system bus 2508 connected to the hosts 2502, 2504 and shared device 2508. The system bus 2508 may be a single system bus 2508 or multiple buses. The system bus 2508 is capable of transmitting control commands between the hosts 2502, 2504 and between the hosts 2502, 2504 and shared device 2506, and is capable of allowing direct data transfers between the a host 2504 and the shared device 2506 independent of the command proxy host 2502. Advanced system bus protocols may be used, such as PCI-e, PCI-e Advanced Switching (“PCIe-AS”), Infiniband, and the like. Where the system bus 2508 is a PCI-e bus, in one embodiment, the shared device 2506 supports PCI-e input/output virtualization (“PCIe-IOV”). Where the shared device 2506 supports PCIe-IOV, the hosts 2602, 2604 may share the shared device 2506 within a single context of one or more contexts. One of skill in the art will recognize other system bus 2508 configurations and types that allow control requests and allow direct data transfers between a host 2504 and the shared device 2506 independent of the command proxy host 2502.

In one embodiment, the shared device 2506 is a first storage device 150 a and the designated command proxy host 2502 is a first server 112 a and the other hosts 2504 are clients 114 a running on the server 112 a or other clients 114. In another embodiment, the shared device 2506 is a first network interface 156 a, the command proxy host 2502 is a first storage device 150 a, and the other hosts 2504 may be a first server 112 a that includes the first storage device 150 a, or another client 114 a, 114 or second storage device 150 b. These embodiments may be configured similar to the in-server SAN system 103 described above in relation to FIG. 1C. The first storage device 150 a may be a solid-state storage device 102 with a solid-stage storage controller 104, as described above, or may be a hard disk drive, optical drive, etc.

FIG. 11 is a schematic block diagram illustrating one embodiment of an apparatus 2600 in a command proxy host for a device shared between multiple hosts in accordance with the present invention. The apparatus 2600, in various embodiments, includes a proxy request receiver module 2602, a proxy request command module 2604, an interrupt receiver module 2606, an interrupt transmission module 2608, a communication path module 2610, and a standard device emulation module 2612, which are described below.

In one embodiment, all or a portion of the modules 2602-2612 of the apparatus 2600 are included in the command proxy host 2502 as depicted. In another embodiment, all or a portion of the modules 2602-2612 of the apparatus 2600 are in another computer, host 2604, server 112, device, etc. controlling the command proxy host 2502.

The apparatus 2600 includes a proxy request receiver module 2602 that receives a proxy request from a requesting host (e.g. 2504 a). The proxy request includes a control request to be executed by the shared device 2506. The control request includes enough information so that the command proxy host 2502 is able to configure the shared device 2506 for a data transfer between the requesting host 2504 a sending the proxy request and the shared device 2506. The information may include address information of the requesting host 2504 a or the shared device 2506, a data identifier, a data length, data source and destination information, intermediate buffer identification, or other pertinent device to allow the command proxy host 2502 to configure the shared device 2506 for the data transfer. The proxy request may be in the form of an interrupt request, comprising the proxy request in whole or in part.

In one embodiment, the proxy request includes enough information to set up a DMA or RDMA transfer between the shared device 2506 and the requesting host 2504 a. In another embodiment, the proxy request includes enough information to set up a broadcast or multicast of the data. One of skill in the art will recognize other pertinent information in the proxy request to set up the shared device 2506 for the data transfer. The proxy request includes enough information for the command proxy host 2502 to set up the shared device 2506 for a data transfer that executes independent of the command proxy host 2502.

The proxy request receiver module 2602 uses the information in the proxy request to generate a control request intended to be sent to and execute on the shared device 2506 to set up the data transfer. The control request is substantially free of data to be transferred between the host and the shared device, but instead typically includes control information to be executed on the shared device 2506. In one embodiment, the control request is executed once by the shared device 2506 so that the shared device 2506 can be part of more than one data transfer with the requesting host 2504 a. For example, the control request may be executed during an initialization process that enables the shared device 2506 and requesting host 2504 a to engage in data transfers at will independent of the command proxy host 2502.

In another embodiment, a control request must be sent for each proxy request associated with a data transfer. For example, the system bus 2508 may have more devices connected than available virtual ports on the shared device 2506 so a control request sent to the shared device 2506 configures or verifies a communication path between the shared device 2506 and the requesting host 2504 a for each data transfer. One of skill in the art will recognize other control requests that may be generated for a proxy request that are to be executed by a shared device 2506 to enable a data transfer between the shared device 2506 and the requesting host 2504 a.

The apparatus 2600 includes a proxy request command module 2604 that transmits the control request to the shared device in response to the proxy request receiver module 2602 receiving the control request. The proxy request command module 2604 typically sends the control request based on address information or other identify information in the proxy request that identifies the shared device 2506. The proxy request receiver module 2602 and the proxy request command module 2604 cooperate to set up the shared host 2506 for data transfers initiated be the requesting host 2504 a.

The interrupt receiver module 2606 and the interrupt transmission module 2608 cooperate to enable direct data transfers between the shared device 2506 and a host 2504 that are initiated by the shared device 2506 by way of an interrupt. The interrupt receiver module 2606 receives an interrupt from the shared device 2606. The interrupt includes information that the shared device has data to be transmitted to a host 2504 and/or has already transmitted data to a host 2504. For example, if the shared device 2506 receives data to be transferred to a host 2504 or initiates a data transfer to a host 2504, the shared device 2506 may have data to be transferred. In another example, if a host 2504 is expecting data, possibly due to a data request initiated by the host 2504, the shared device 2506 may transfer data to a specified memory buffer in the host 2504 and the shared device 2506 will send an interrupt after the data transfer indicating completion of the transfer.

The interrupt transmission module 2608 transmits the information included in the interrupt to the host 2504. The information is sufficient for the host 2504 receiving the information to continue a process of receiving the data transmission. In one embodiment, the information allows the host 2504 to prepare to receive data of a data transfer. In another embodiment, the information allows the host 2504 to recognize that a data transfer from the requesting device 2506 is complete and to then use the data as necessary. In one embodiment, the information causes host 2504 to identify a new memory buffer location and communicate this directly or indirectly through the command proxy host to the shared device 2506. In one embodiment, the information is derived from the interrupt and transmitted to the host 2504. In another embodiment, the interrupt is forwarded to the host 2504. One of skill in the art will recognize information that may included in an interrupt to be transmitted by the interrupt transmission module 2608 to continue a process of receiving a data transmission.

The command proxy host 2502 is capable of servicing the interrupt. In one embodiment, the command proxy host 2502 can service interrupts from the shared device 2506 and the other hosts 2504 are incapable of servicing interrupts from the shared device 2506. In another embodiment, the command proxy host 2502 and other hosts 2504 are able to service interrupts, but the command proxy host 2502 is designated to service interrupts from the shared device 2506.

In the preferred embodiment, the data transfer between the host 2504 and the shared device 2506 is independent of the command proxy host 2502. In one embodiment, the data transfer is a DMA transfer between the host 2504 and the shared device 2506. In another embodiment, the host 2504 and the shared device 2506 transfer data using an RDMA transfer. In one embodiment, the data transfer is initiated by the host 2504 either to directly transfer data to or from the shared device 2506 or to set up a DMA or RDMA. In other embodiments, the data transfer is part of a broadcast or multicast. In any case, the data transfer is independent of the command proxy host 2502.

In one embodiment, the apparatus 2600 includes a path module 2610 that determines if a communication path exists between a host 2504 and the shared device 2506. The communication path may be a data path or a command path or both. The path module 2610 also creates the communication path if the communication path does not exist. For example, if a system bus 2508 has more connected devices than virtual ports, the path module 2610 first determines if a desired communication path exists between a host 2504 and shared device 2506 and creates the communication pathway if the system bus 2508 ports are not configured with a communication path between the host 2504 and shared device 2506.

Typically the path module 2610 determines if a communication path exists in response to the proxy request receiver module 2602 receiving a proxy request from the requesting host 2504 a or an interrupt from the shared device 2506. The communication path created by the path module 2610 is sufficient to transfer data or control requests or both between the host 2504 and the shared device 2506. In another embodiment, the path module 2610 receives a proxy request or an interrupt and creates the communication path once, during initialization. In another embodiment, the module 2610 determines if a communication path exists after each proxy request or interrupt. One of skill in the art will recognize other times when the path module 2610 can determine if a communication path exists and then create the communication path if it does not exist.

In one embodiment, the apparatus 2600 includes a standard device emulation module 2612 that emulates a device to one or more of the hosts 2504 as a standard device attached to the system bus 2508 prior to loading the hosts 2504 with code specific to the operation of the device. The standard device is supported by an industry standard BIOS. In a preferred embodiment, the device emulated by the standard device emulation module 2612 is the shared device 2506. For example, if the shared device 2506 includes functionality that is not supported by a standard driver supported by a host 2504, the standard device emulation module 2612 emulates a standard device supported by the host 2504 at initialization or until the standard device emulation module 2612 can load a driver specific to functionality specific to the shared device 2506. This bootstrapping operation allows the host 2504 to view and access the shared device 2506 in a limited way until a driver for the shared device 2506 is loaded into the host 2504. In one embodiment the standard device emulation module 2612 supports I/O virtualization.

The system bus 2508 may include a non-transparent port. A non-transparent port is able to block a device attached to the non-transparent port during an initialization and device discovery operation so that the device executing the discovery/initialization cannot access the device connected to the non-transparent port. In one embodiment, the system bus 2508 includes a system bus switch with a non-transparent port. In this embodiment, a first initialization process executing on a host 2504 discovers at least the command proxy host 2502 to the host 2504 and is unable to discover the shared device 2506. In the embodiment, the discovered command proxy host 2602 is identified for communication with at least the host 2504 executing the first initialization process as a result of the first initialization process.

In another embodiment, a second initialization process executing on the command proxy host 2502 discovers at least the shared device 2506 to the command proxy host 2502, where the shared device 2506 is identified for communication with at least the command proxy host 2602 as a result of the initialization process.

For example, where a storage device 150 accesses a network interface 156 independent of a server 112, the non-transparent port may hide the network interface 156 during an initialization process by a server 112 (acting as a command proxy host 2502) but may allow the storage device 150 to be discovered for communication. In this case, the storage device 150 acts as the shared device 2506 to the first server 112 a and other servers 112 are able access the storage device 150 based on the discovery done by the first server 112 a.

In a second initialization process, the network interface 156 acts as the shared device 2506 and the storage device 150 acts as the command proxy host 2502 so in the second initialization process by the storage device 150 acting as command proxy host 2502 and root, the storage device 150 then discovers the network interface 156 for communication. The storage device 150 then can communicate to the network interface 156 independent of the servers 112. In another example, a server 112 acts as command proxy host 2502 to enable direct communication between the storage device 150 and the network interface 156.

FIG. 12 is a schematic block diagram illustrating one embodiment of an apparatus 2700 associated with a shared device 2506 for a device shared between multiple hosts 2502, 2504 in accordance with the present invention. The apparatus 2700 includes, in various embodiments, a shared device control request receiver module 2702, a control request response module 2704, and an interrupt transmission module 2706, which are described below. All or a portion of each of the modules 2702-2706 of the apparatus 2700 may execute in the shared device 2506 or in another device controlling the shared device 2506.

The apparatus 2700 includes a shared device control request receiver module 2702 that receives a control request from the command proxy host 2502 after the command proxy host 2502 receives a proxy request from a requesting host 2504 a. The control request response module 2704 configures the shared device 2506 for a data transfer between the requesting host 2504 a and shared device 2506. The control request does not include data of the data transfer, but may include information sufficient to set up a DMA between the host 2504 a and shared device 2506 or other data transfer operation. The control request may set control registers in the shared device 2506, or may configure a communication path between the shared device 2506 and requesting host 2504 a.

The apparatus 2700 includes an interrupt transmission module 2706 that transmits an interrupt to the command proxy host 2502. The interrupt is then sent to a host 2504 and includes enough information for the host 2504 to continue a process of receiving the data of the data transfer. In one embodiment, the interrupt transmission module 2706 sends an interrupt after the shared device 2506 receives data from another device, such as a storage device 150 or client 114. In another embodiment, the interrupt transmission module 2706 sends an interrupt for transfer of data on the shared device 2506, for example where the shared device 2506 is a storage device 150. In another embodiment, the interrupt transmission module 2706 sends an interrupt in response to a request from the host 2504. The host 2504 may request data and then continue other tasks and then the shared device may then command the interrupt transmission module 2706 to send an interrupt when the requested data is ready for transfer. One of skill in the art will recognize other reasons for the interrupt transmission module 2706 to send an interrupt.

FIG. 13 is a schematic block diagram illustrating one embodiment of an apparatus 2800 operating in conjunction with a requesting host 2504 a for a device shared between multiple hosts in accordance with the present invention. The apparatus 2800 includes a proxy request transmitter module 2802, a host data transmitter module 2804, a host interrupt receiver module 2806, and a host data receiver module 2808, which are described below. All or a portion of each of the modules 2802-2808 of the apparatus 2800 may execute in a host 2504 or in another device controlling the host 2504.

The apparatus 2800 includes a proxy request transmitter module 2802 that that transmits a proxy request from a requesting host 2504 a to a designated command proxy host 2502. The command proxy host 2502 then transmits a control request to the shared device 2506 based on the proxy request. The control request executes on the shared device 2506 to set up the shared device 2506 for a direct data transfer between the requesting host 2504 a and the shared device 2506.

The apparatus 2800 includes a host data transmitter module 2804, executing on the requesting host 2504 a, that initiates transfer of data between the requesting host 2504 a and the shared device 2506. The data transfer executes independent from the command proxy host 2502. The requesting host 2504 a may transfer the data or may set up a DMA or RDMA transfer directly or through the proxy request. The data transfer may be to the shared device 2506 or may to another device accessible through the shared device 2506. One of skill in the art will recognize other ways for the requesting host 2504 a to initiate a data transfer where the data is transferred independent from the command proxy host 2502.

In one embodiment, the apparatus 2800 includes a host 2504 interrupt receiver module 2806, executing on a host, that receives information from the command proxy host 2502 that the shared device 2506 has data to be transmitted to the host 2504 and/or already transmitted data to the host 2504. The information is derived from an interrupt received by the command proxy host 2502 from the shared device 2506. The host data receiver module 2808 then continues a process of receiving the data transmission. The data transmission executes independent from the command proxy host 2506. Where the shared device 2506 has data to be transferred, the host data receiver module 2808 may set up buffers, signal the shared device 2506 that the host 2504 is ready for the data transmission, etc. to continue the data transfer process. Where the shared device 2506 has already transferred the data, the host data receiver module 2808 may signal completion of the transfer, may move the data, etc. to continue and complete the data transmission.

FIG. 14 is a schematic flow chart diagram illustrating a first embodiment of a method 2900 for a device shared between multiple hosts in accordance with the present invention. The method 2900 begins 2902 and the proxy request receiver module 2602 that receives 2904 a proxy request from a requesting host 2504 a. The proxy request command module 2604 transmits 2906 a control request to the shared device 2506 and the method 2900 ends 2908. The control request is execute by the shared device 2506. The control request is generated from the proxy request and is sufficient to configure the shared device 2506 for a data transfer between the shared device 2506 and the requesting host 2504 a. The data transfer executes independent of the command proxy host 2502.

FIG. 15 is a schematic flow chart diagram illustrating a second embodiment of a method 3000 for a device shared between multiple hosts in accordance with the present invention. The method 3000 begins 3002 and the shared device control request module 2702 receives 3004 a control request from the command proxy host 2502. The control request is generated at the command proxy host 2502 from a proxy request received from a requesting host 2504 a. The control request response module 2704 configures 3006 the shared device 2506 for a data transfer between the requesting host 2504 a and the shared device 2506 and the method 3000 ends 3008. The control request does not contain data of the data transfer and the data transfer executes independent of the command proxy host 2502.

FIG. 16 is a schematic flow chart diagram illustrating a third embodiment of a method 3100 for a device shared between multiple hosts in accordance with the present invention. The method 3100 begins 3102 and the proxy request transmitter module 2802 transmits 3104 a proxy request from a requesting host 2504 a to a designated command proxy host 2502. The command proxy host 2502 then sends a control request generated from the proxy request to the shared device 2506. The host data transmitter module 2804 initiates 3106 transfer of data between the requesting host 2504 a and the shared device 2506 independent of the command proxy host 2502 and the method 3100 ends 3108. The proxy request does not include data of the data transfer.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

1. An apparatus for sharing a device between multiple hosts, the apparatus comprising: a proxy request receiver module, executing on a designated command proxy host, that receives a proxy request from a requesting host, the requesting host comprising one of two or more hosts, wherein each of the two or more hosts execute an operating system independent from the other hosts and a shared device, and wherein one of the two or more hosts is designated as the command proxy host, the two or more hosts and the shared device connected through a system bus, the proxy request comprising a control request to be executed by the shared device, the control request sufficient to configure the shared device for a data transfer between the requesting host sending the proxy request and the shared device, the data transfer executing independent of the command proxy host, the control request being substantially free of data to be transferred between the requesting host and the shared device; and a proxy request command module, executing on the command proxy host, that transmits the control request to the shared device in response to the proxy request receiver module receiving the control request.
 2. The apparatus of claim 1, further comprising: an interrupt receiver module, executing on the command proxy host, that receives an interrupt from the shared device, the interrupt comprising information that the shared device has one or more of data to be transmitted to a host and has already transmitted data to a host; and an interrupt transmission module that transmits the information included in the interrupt to the host, the information sufficient for the host receiving the information to continue a process of receiving the data transmission.
 3. The apparatus of claim 2, wherein the hosts other than the command proxy host are incapable of receiving the interrupt.
 4. The apparatus of claim 1, further comprising a path module, executing in the command proxy host, that determines if a communication path exists between a host and the shared device, the communication path comprising one or more of a data path and a command path, and that creates the communication path in response to determining that the communication path does not exist, the data path being sufficient to transfer one or more of data and control requests between the host and the shared device.
 5. The apparatus of claim 4, wherein the communication path module determines if a communication path exists in response to one of a proxy request from the host and an interrupt from the shared device.
 6. The apparatus of claim 1, wherein the shared device comprises a network interface that transfers data received from one of the two or more hosts over a computer network to a device and transfers data received through a computer network from a device to one of the two or more hosts.
 7. The apparatus of claim 1, wherein the shared device comprises one or more of a storage device and a storage controller.
 8. The apparatus of claim 7, wherein the storage device further comprises a solid-state storage device and the storage controller comprises a solid-state storage controller.
 9. The apparatus of claim 1, wherein the system bus comprises a peripheral component interconnect express (“PCI-e”).
 10. The apparatus of claim 9 wherein the PCI-e bus and the shared device supports PCI-e input/output virtualization (“PCIe-IOV”).
 11. The apparatus of claim 10 wherein two or more of the two or more hosts share the shared device within a single context.
 12. The apparatus of claim 1, wherein the command proxy host executes in one of: a root; one of the two or more hosts; the shared device; a third party element managing commands to the shared device independent of the two or more hosts; and a device that combines one or more of: the root, the one of the two or more hosts; the shared device; and the third party element managing commands.
 13. The apparatus of claim 1, wherein the independent operating systems include a virtual machine layer with one or more operating systems operating above the virtual machine layer.
 14. The apparatus of claim 1, wherein the shared device uses one of direct memory access (“DMA”) and remote direct memory access (“RDMA”) to transfer data between the host identified in the control request and the shared device.
 15. The apparatus of claim 1, further comprising a standard device emulation module, executing on the command proxy bus, that emulates a device to one or more of the hosts as a standard device attached to the system bus prior to loading the one or more hosts with code specific to the operation of the device, the standard device being supported by an industry standard BIOS.
 16. The apparatus of claim 15, wherein the device emulated by the standard device emulation module comprises the shared device.
 17. The apparatus of claim 15, wherein the standard device emulation module for the standard device supports I/O virtualization.
 18. The apparatus of claim 1, wherein the system bus further comprises a system bus switch with a non-transparent port, wherein a first initialization process executing on a host discovers at least the command proxy host to the host and is unable to discover the shared device, wherein the discovered command proxy host is identified for communication with at least the host executing the first initialization process as a result of the first initialization process.
 19. The apparatus of claim 18, wherein a second initialization process executing on the command proxy host discovers at least the shared device to the command proxy host, wherein the shared device is identified for communication with at least the command proxy host as a result of the initialization process.
 20. An apparatus for sharing a device between multiple hosts, the apparatus comprising: a shared device control request receiver module, executing on the shared device, that receives a control request from a host designated as a command proxy host, the command proxy host comprising one of two or more hosts, wherein each of the two or more hosts execute an operating system independent from the other hosts and the shared device, the two or more hosts and the shared device connected through a system bus, the command proxy host transmitting the control request in response to receiving a proxy request from a requesting host, the requesting host comprising one of the two or more hosts; and a control request response module, executing on the shared device, that configures the shared device for a data transfer between the requesting host and the shared device, the control request being substantially free of data of the data transfer, the data transfer executing independent of the command proxy host.
 21. The apparatus of claim 20, further comprising: an interrupt transmission module, executing on the shared device, that transmits an interrupt to the command proxy host, the interrupt comprising information that one of the shared device has data to be transmitted to a host and the shared device has transferred data to a host, the information sufficient for the host to continue a process of receiving the data, wherein the command proxy host transmits the information to the host.
 22. An apparatus for sharing a device between multiple hosts, the apparatus comprising: a proxy request transmitter module that transmits a proxy request from a requesting host to a designated command proxy host, the requesting host and the command proxy host each comprising one of two or more hosts and a shared device connected to a system bus, wherein each of the two or more hosts execute an operating system independent from the other hosts and the shared device, the proxy request comprising a control request to be executed by the shared device, the command proxy host transmitting the control request to the shared device, the control request sufficient to configure the shared device for a data transfer between the shared device and the requesting host transmitting the proxy request, the control request being substantially free of data to be transferred between the requesting host and the shared device; and a host data transmitter module, executing on the requesting host, that initiates transfer of data between the requesting host and the shared device, the transfer executing independent of the command proxy host.
 23. The apparatus of claim 22, further comprising: a host interrupt receiver module, executing on a host, that receives information from the command proxy host that the shared device has one or more of data to be transmitted to the host and already transmitted data to the host, the information derived from an interrupt received by the command proxy host from the shared device; a host data receiver module that continues a process of receiving the data transmission, the data transmission executing independent of the command proxy host.
 24. An system for sharing a device between multiple hosts, the system comprising: a system bus; a shared device connected to the system bus; two or more hosts connected to the system bus, wherein each of the two or more hosts execute an operating system independent from the other hosts and the shared device, and wherein one of the two or more hosts is a designated command proxy host; a proxy request receiver module, executing on the command proxy host, that receives a proxy request from a requesting host, the proxy request sufficient to configure the shared device for a data transfer between the requesting host sending the proxy request and the shared device, the data transfer executing independent of the command proxy host, the control request being substantially free of data to be transferred between the requesting host and the shared device; and a proxy request command module, executing on the command proxy host, that transmits the control request to the shared device in response to the proxy request receiver module receiving the control request.
 25. The system of claim 24, further comprising: an interrupt receiver module, executing on the command proxy host, that receives an interrupt from the shared device, the interrupt comprising information that the shared device has one or more of data to be transmitted to a host and has already transmitted data to a host; and an interrupt transmission module that transmits the information from the interrupt to the host, the information sufficient for the host receiving the information to continue a process of receiving the data transmission.
 26. A computer program product comprising a computer readable medium having computer usable program code executable to perform operations for sharing a device between multiple hosts, the operations of the computer program product comprising: receiving a proxy request from a requesting host, the requesting host comprising one of two or more hosts, wherein each of the two or more hosts execute an operating system independent from the other hosts and a shared device, and wherein one of the two or more hosts is designated as the command proxy host, the two or more hosts and the shared device connected through a system bus, the proxy request comprising a control request to be executed by the shared device, the control request sufficient to configure the shared device for a data transfer between the requesting host sending the proxy request and the shared device, the data transfer executing independent of the command proxy host, the control request being substantially free of data to be transferred between the requesting host and the shared device; and transmitting the control request to the shared device in response to the proxy request receiver module receiving the control request.
 27. A computer program product comprising a computer readable medium having computer usable program code executable to perform operations for sharing a device between multiple hosts, the operations of the computer program product comprising: receiving a control request from a host designated as a command proxy host, the command proxy host comprising one of two or more hosts, wherein each of the two or more hosts execute an operating system independent from the other hosts and the shared device, the two or more hosts and the shared device connected through a system bus, the command proxy host transmitting the control request in response to receiving a proxy request from a requesting host, the requesting host comprising of the two or more hosts; and configuring the shared device for a data transfer between the requesting host and the shared device, the control request being substantially free of data of the data transfer, the data transfer executing independent of the command proxy host.
 28. A computer program product comprising a computer readable medium having computer usable program code executable to perform operations for sharing a device between multiple hosts, the operations of the computer program product comprising: transmitting a proxy request from a requesting host to a designated command proxy host, the requesting host and the command proxy host each comprising one of two or more hosts and a shared device connected to a system bus, wherein each of the two or more hosts execute an operating system independent from the other hosts and the shared device, the proxy request comprising a control request to be executed by the shared device, the command proxy host transmitting the control request to the shared device, the control request sufficient to configure the shared device for a data transfer between the shared device and the requesting host transmitting the proxy request, the control request being substantially free of data to be transferred between the requesting host and the shared device; and initiating transfer of data between the requesting host and the shared device, the transfer executing independent of the command proxy host. 